The Construction of Space Shuttle Launch Complex 39-B

A very personal and technical written and photographic history, by James MacLaren.

Looking down from the Left (RSS Side 4) Vehicle Access Platform at elevation 191'-0".

There were two of them. Right and Left. RSS Side 2 and RSS Side 4. Facing each other across a gap which would be filled with the forward end of the Space Shuttle's fuselage when the RSS was mated to it.

And we got a peek at the far, flip-up part, end of one of them on the previous Page, and I mentioned that it was a really cool place to go, in and of itself, and also, "or maybe snap a photograph from what constituted a quite-interesting and unusual point of view", and the one across the way, over on the Hinge Column side of the RSS where the photograph you're seeing above was taken from, was equally well-endowed in both respects.

And as regards the photograph... where to begin?

This image contains such a huge amount of information, technical, operational, and just general "slice of life", that I'm really not sure where this part of the story is going to take me, but of course that's one of the most deliciously-fun aspects of being writer, and that's the part where "you give yourself over to it," having no idea where it's going to go, allowing the muse to move in, take full command of things, and then, even as the words are literally pouring off of the ends of your own fingers, you find yourself to be a spectator to things.

It's not even you, anymore.

I'm feeling it strongly, right this second, even as an unbidden torrent of more and more letters of the alphabet continues to assemble, self-arrange, and grow across and down my computer screen, completely on its own, without any sensible, conscious, input that's actually coming from me.

The sensation is utterly indescribable, and is also utterly delicious, and right now, I could not possibly care less about "the rules of order" and rigid adherence to some damn made-up set of instructions for doing this stuff.

I'm having too much fun.

Leave me alone!


Ok, back to the picture.

What the hell's going on here, anyway?

That's the Pad Deck down there, a little over one hundred forty feet beneath your point of view, hanging dangerously out against and beyond the piece of removable handrail that sits at the terminal end of the flip-up portion of the Vehicle Access Platform you're standing on, all alone.

The platform you're standing on is one of the most out-of-the-way locations you can get to, short of walking high steel, on the whole RSS. All of these Vehicle Access Platforms, the whole set, three of them in descending order over on the Column Line 7 side of things, and this single one over on the Hinge Column side of things, were pesty to get to, but at least the ones over on the far side could be gotten to by climbing down (although heading back was strictly an uphill affair), but this one did not even have that much going for it.

You start from the ground. You start from the Pad Deck.

From there, it's either Stair Tower 3, over on Column Line 7, or it's the FSS Elevators. No other options for getting up on the steel, unless they decide to give you a ride in the Skip Box, but that's not happening, so we can forget that.

And we can forget Column Line 7, too. Straight up Stair Tower 3, hoofing it the whole way.

Better to save time and energy using the FSS Elevators, get out at the 140'-0" level, and take the crossover catwalk that ran across the Hinge Column and Struts area, past RSS Column Line 2, to the RSS Main Floor at elevation 135'-7".

But then what?

For the far side of things, for accessing the Vehicle Access Platforms over on the Column Line 7 side of things on the RSS, you had the option of taking the FSS Elevator all the way up to elevation 220'-0", and then walking across the crossover catwalk up there to get to the RSS Roof at elevation 211', and then you could continue to your destination by heading down from there, using Stair Tower 4, and then you could keep going down still using Stair 4, and leave the tower when you were done, by crossing the width of the RSS at elevation 135'-7" and then take the crossover catwalk to the FSS down there at elevation 140'-0", and grab the elevator, once again, and down to the ground you go, nice and easy.

But not over here. Not on this side. You may or may not remember, but we've already discussed Stair Tower 5, in a quite-substantial level of detail I might add, explaining why it had to be the way it was, and Stair Tower 5 did not make it all the way up to the RSS Roof at elevation 211' which you could reach via the FSS Elevators and from where you could then head down, and instead only made it as far up as the top level of the PCR Fixed Platforms at elevation 187'-1", and then, across from there, heading out toward the face of the RSS, it also connected to a catwalk that took you all the way out to our Vehicle Access Platform on the Hinge Column side of things, at elevation 191'-0".

So you got to this little platform by climbing to it, up the full height of Stair 5, or you didn't get to it at all. And stair 5 was as much a ship's ladder as it was a proper stair, which meant it was no fun to have to traverse, and with something (or even several somethingS) in your hands, it was just that much more no fun. And from there you kept on hoofing it until you were all the way out there.

People, very naturally, stayed the hell away from Stair 5.

And in so doing, they stayed the hell away from this little platform.

Splendid Isolation does not even begin to describe it.

One of my very favorite places on the whole tower.

Later, (years later) when I came back to work on Pad B with Ivey, and after we hung the OMBUU on the RSS, you could sort of cheat a little bit with access to this platform at 191'-0" by taking the FSS Elevator up to level 160'-0" and use the crossover catwalk to the OMBUU, and then from there, climb up the stairs inside of the OMBUU, and then, from the OMBUU's "roof", you could take the ladder which got you to a place near the end of the catwalk coming over from the top of Stair 5, but even then it was more trouble than it was worth, because the OMBUU was insanely cramped and filled up with all the ridiculous plumbing and paneling, and hard edges, and sharp edges, and wiring, and everything else you need to safely play around with industrial quantities of cheerful stuff like liquid oxygen (yeeks) and liquid hydrogen (fuhgeddaboudit), and the "stairs" were really ship's ladders (again), and you'd tear your clothes on some of that crap trying to squeak around it up there, and even if you didn't, it was still a pain in the ass, and...

...Splendid Isolation.

Right slap downtown.

Right slap in the middle of everything out there, high up on the exposed face of the RSS with the looming cantilevered darkness of the RCS Room's empty cavern blotting out half of the sky above you, and yet, paradoxically, with no way for anybody to get anywhere near you.

With an impossible overabundance of insanely cool stuff all around you in every direction, up, down, all around...

...and nobody could get to you.

Yeah, one of my most very favorite places in the whole joint.

Ok, what's going on out there?

Along the bottom margin of the photo at the top of the page, on the left side you can see the white shape of the compressible bumper for the flip-up platform you're standing on, covered in painter's tarp, and on the right side, even whiter (it's not covered in paint splatter), you can see the Left Side Seal Panel angling toward the bottom-right corner of the frame.

When you look at the narrow side of the Side Seal Panel, the one which will face the Orbiter when it's mated, you can see that they're either getting ready to, or have just finished, working on the Inflatable Seal that lives there, and you can clearly see that the pair of galvanized strips that hold the Inflatable Seal to the Panel are there, but are just kind of tacked in place here and there, and are not fully screwed-down to the Side Seal Panel, and have a wavy disorganized look about them, and whatever's going on here with this stuff isn't done yet, one way or the other.

The right margin of our photograph is dominated by the PCR Doors, and you're seeing them in the half-open/half-shut position that they spent almost all of their time in. This positioning matches pretty well, what was depicted (in light blue) on the drawing I used on the previous page to show you the Torque Tubes and the small platforms that gave you access to the equipment used to install or remove them from the Orbiter's Payload Bay Doors.

And that's probably not a coincidence, either. Despite my snarky comment on that drawing, the "extra" door on the drawing, the one shown in light blue, is looking pretty close to the configuration (and is very likely the exact configuration) the doors would assume, mid-travel, between full-open and full-shut, where the bend between the "inboard" and "outboard" panels was sharpest, and the clearance between the two panels of the bi-fold door was at its absolute minimum.

I can guess that this was put on the drawing to let people see how things looked in there, in the crook of that sharp angle, to get a sense of the minimal clearances (not much at all) between the Access Platforms, the Torque Tubes and their Manipulator Arms, and the Door Panels themselves (and to get a sense of just how cramped things are in there, you might want to take note of the cutout in the "inboard" Door Panel over in there, where the "tube" side of the Torque Tube goes, that the "arm" part of the Torque Tube needs for clearance to keep it from interfering with the Door, and even with that, the other side of the "arm" is still getting into the Ladder they had to climb, in order to get up on the Platforms), and in this configuration, the Doors (excepting the narrow space between the two panels) are providing the greatest degree of open space and freedom to get to things, both inside and outside the Payload Changeout Room.

Inside the PCR, over in that corner over there, there was a lot of stuff going on, and Outside the PCR, in the area around the curved Orbiter Mold Line cutout in the 135'-7" floor steel, there was even more stuff going on, and the Doors were a nuisance, and blocked access to a lot of ongoing work that needed doing, and so, unless there was some sort of actual need to put them in some other position, this was the position you would invariably find them in, and this is the position you'll see them in most times in my photographs. In this image, you can see where the Doors are blocking access when they're fully-open. And in this image, you can see where the Doors are blocking access when they're fully-closed. Blink back and forth between them if you want to, to see how things changed between the configurations. I've overstated things a little, for the purposes of illustrating what's going on with the PCR Doors, and in fact there was a little access with both configurations, but it wasn't nearly enough to get any proper tooling and/or equipment in there to do any sensible work, and so I just went ahead and said there was no access at all, but that's not really the full and complete truth, ok?

And both blocked areas were high-volume high-traffic work areas for all of the craft labor groups, structural, mechanical, and electrical.

With the Doors fully-closed, blocking the area out along the Orbiter Mold Line, that might seem reasonable, considering all the action going on with flip-ups, Side Seal Panels and their Actuators, Canister Guide Rails, the floor steel, and a whole lot more, too. On top of that, with the Doors closed, the LRU Strongbacks started encroaching in on you, in the interior of the PCR, and the Fixed Interior Platforms they were bolted to were also kind of crowding in on you in there, too. The other way about, with the Doors fully-open, might not seem as bad, but that's because the drawings are not showing us all of the mechanical and electrical stuff that ran full-height, floor to ceiling, interior and exterior to the surface of the PCR Walls over there, and of course the Walls weren't going to be building themselves, either.

And so it devolves to what's our best possible compromise here, to keep the PCR Doors (which went in early, because they had to or otherwise an awful lot of follow-on work's not getting done until they're in there and that's going to cascade down through everybody's schedule and wind up costing everybody an awful lot of money and an awful lot of time, even though the Doors took up a lot of room) as far out of the way as we can, to allow the greatest number of people to keep doing their work, and the photograph at the top of this page is showing that compromise, and that's where the doors stayed put, for the lion's share of the time.

So now you know how that works.

And have I repeated myself enough with "It's all for a reason. Every last bit of it." yet?

No?

Very well then, it's all for a reason. Every last bit of it.

Between the Doors, resting on the PCR Floor at elevation 135'-7", somebody has their swing stage sitting there on the RSS Main Floor at elevation 135'-7", and they're definitely using the LRU Lifting Lines to raise it and lower it, but when the photograph was taken, it was not directly hooked on to the lifting lines. You can see the LRU Lifting Lines sheave blocks with their four-part lines, right there hovering just above either end of it, and this just so happens to give us a pretty good look at where the LRU (which will never be visible in any of our photographs because it was furnished "by others" after I departed the Pad) lift points are, down on the floor steel. This is the same stuff that comes down through those oddball cocked-angle tube steels up in the RCS Room.

I have no idea who's stuff this was. Painters? Pipefitters? Electricians? Sprinklerfitters? No idea. Nor do I have the faintest idea what they might have been doing with it.

NASA was pretty good about letting us contractors use their lifting gear. Anything that could speed the process, even just a little bit, was to be desired, and a fair amount of the use of this stuff was done on verbals, no paperwork, on-the-fly as the work progressed. Everybody got along pretty well for the most part, and once you'd demonstrated competence in your craft and an agreeable level of honesty and integrity, lots of times all it took was a walk across to their field trailer to ask them for permission, which, if the equipment in question was not tied up in some other operation, or test, or whatever, they'd cheerfully allow, and that was pretty nice, all the way around.

Across the way over there, they're working on installing the Inflatable Seals that are mounted on the Orbiter Side Seal Panel and if you look, you can see somebody wearing an orange hard hat in a spider basket, down toward the bottom of the Panel, in the process of fastening that Inflatable Seal, which is kind of flapping in the breeze, up above him.

And left of that... things get hairy.

So... get ready for it.

And right here, I feel it necessary to give fair warning in advance, because we're about to embark upon an incredible journey down into the drawings, trying to figure out what, exactly it is that we're seeing in the highlighted area on the image I just linked to, and this particular journey is very likely not for everybody, and only the most dedicated, only those who are deeply curious, are going to want to follow along through the coming labyrinth, and if you're not one of those people, that's perfectly fine and you can maybe skip what's coming, ok? I'll give you some kind of notice farther down, maybe in boldface type down there somewhere, that it's safe to come back outside to play in the yard again, ok?

For those who are still with me, I want you to know the tower. I want you to feel at home on the tower. And the tower is one of the most extraordinary, most astounding, most complex, most highly-ramified, and most uncanny constructs that has ever been assembled by human hands, and as with anything else at this level, it cannot simply be slapped at, cannot simply be glanced at, and you cannot dismiss it with a wave of your hand and a curt "I don't have time for all that," and then expect to have any idea whatsoever as to what it is that you're looking right at.

Elon Musk calls his Launch Facility "Stage Zero," as though it was an integral part of the rocket itself, coming before the first stage, the second stage, and such upper stages as might be stacked on top of that.

And I quote: "Stage Zero, which is everything needed to launch & catch the rocket, is at least as hard as the booster or ship."

So you're about to embark on some pretty substantial stuff, ok?

Ok.

We've encountered more than enough chance alignments of structural steel already in this thing, but we're certainly not done, and we're hitting one here that should give you pause, and make you start wondering if anything you've seen so far is really what you think it is.

And for this one, it launches off into The World of the Ridiculous, and we will find it to be jam packed with a lot of stuff, a lot of which will be visible only as inscrutable slivers and slices, all of which will very deviously add up in a bland and unnoticeable way to make you think you're looking at one, or maybe two things, when in fact, you're looking at a lot more than that, and the things you're looking at may very well be ten, twenty, thirty, or more, feet apart from each other even though they look like they're right next to each other, or are even all integrally part of a single thing.

So we begin by cutting most of the photograph away, giving ourselves better focus, and a better chance of figuring this stuff out.

And although it's clear that we're looking down along a significant vertical extent of steel, the devil is in the details, and the vertical relationships between things in this image are anything but clear.

For perspective on the whole area of interest visible in the original photograph up at the top of this page, I've constructed another one of those "You're Standing Here" "Your Field of View" images based on the contract drawings, but this time I've altered the contract drawing itself, significantly, and the alterations include removal/cleanup of extraneous items that would only serve to clutter things up, confusingly, coupled with insertions, from three separate other contract drawings, to include relevant steel which is very-much visible in the photograph, and then, after that was done, I faded all the steel that's not visible in the photograph, and although it's certainly not perfect, it seems to at least not be misleading, and here it is here to give you an overview of what you're actually seeing in the photograph we're looking at.

Every bit of what's bolded/highlighted on the drawing inside the light-blue shaded area is visible, in part (and sometimes the "part" is the thinnest of thin slivers), or in whole, to the left of and below, the Canister Guide Rail which will be our anchor for what's coming.

So we'll start out with that easiest part, the Canister Guide Rail, which is a W10x49, the dimensions for which can be found in the Steel Book, and we'll use this as our starting point, and it's actually a pretty good one, 'cause it has hard numbers associated with it, and in cases like the one we're just now entering, the more hard numbers you can get, the better.

We're looking down from above at a fairly steep angle, and the part of the Canister Guide Rail that's visible in the photograph runs from its bottom end at elevation 133'-11½", all the way up to around elevation 164' or so (and I've worked that part out, using what I'm about to walk you through with what's visible here, and you'll get to see how it was done, as we go along, ok?).

So the visible part of the guide rail in the photograph runs as shown here in a simplified drawing, and also shown here too, as part of our "field of view" embedded within the more-confusing background of the overall whole.

And now that we've been given a vertical bracketing with the Guide Rail, let us proceed, vertically, from the top down, with the identifications of all of that iron that's right there next to it.

And the highest item (closest to the camera) is going to be our Vehicle Access Platform at elevation 158'-2". And here you see it, on the structural drawings, sheet S-36.

Here it is here on the photograph, identified. Here it is again, with its main features labeled. Some of you might be asking questions to yourself about it, thinking, hmmm.... that doesn't look quite right, and if so, that's probably because it's not properly "square", and instead has a sort of "offset," right at the hinge line, and the dimensions given for the locations of the "outboard" framing members for both halves of this platform on S-36 bear this out.

Here it is again, one more time, in elevation view, with the hinge called out. All three of these Vehicle Access Platforms over on the Column Line 7 side of the RSS were similar, but all of them were different, too. Each one had its own personality and layout.

Next item, heading downward along the side of the Canister Guide rail will be that ever-so-peculiar-looking, and ever-so-easily-identifiable, Curved Monorail End Piece for the 2-Ton Monorail Hoist that rolls along overhead the PBK & Contingency Platforms. There is support steel, underneath which it is hung, but that stuff is some of the trickier things in view and we're going to skip over that whole part of things with the exception of the endmost transverse member that's holding it up, and just stick with the Monorail itself, and not even the whole Monorail. Just the end of it with the weird-looking curved part on hinges, yet another thing that flips-up, which sticks out beyond the Canister Guide Rail, and needs to be hinged, so it can be flipped up, out of the way, when the RSS swings around and closes in on the Orbiter, or otherwise it will hit the Orbiter, and no, we're not going to be letting that kind of thing happen. So it gets a hinge. And of course, in similar fashion as was mentioned (But not fully explained, and that's coming, but not right now, ok?) earlier with the Right Orbiter Side Seal Panel, owing to the curious nature of the RSS's exact direction of travel for things beyond the plane of Column Line B, toward Line C, as it closes in on the Orbiter, the hinged nature of this monorail beam, over here on the right side of things, turned out to be unnecessary, but so far as I know, they left the hinge on this thing alone, instead of welding it in place like they did with the Side Seal Panel over on this (Right, RSS Side 2) side.

Here it is here, highlighted. And here it is again, labeled.

The hinged portion of this monorail was surprisingly elaborate, and had several items included as part of the structure that you do not see with stuff like this on a regular basis. They beefed it up pretty good, and then on top of that, included some other interesting stuff, too.

This thing has always intrigued me, and clearly, they needed the hoist it carries, or perhaps whatever might be dangling beneath the hoist in suspension, or perhaps both, to be able to roll a little sideways along their vertical, lifting, axis, while they were rolling along horizontally, just as they were approaching the side of the Orbiter in closest proximity, but why, is a question I've never gotten a clear answer to.

My gut feeling on it is that the hoist drum, which runs longways along the length of the monorail (and about that little item, the clocking of the hoist drums, an astounding amount more, later on, but definitely not now, ok), which puts the drum's forward extremity out sufficiently ahead of the trolley that's carrying it, as to cause it to want to interfere with the Orbiter when it gets too close, and whatever they were doing over here with that hoist (and it served several different functions) and the things it was lifting, needed to be as close as possible to the Orbiter as they could get it, so with the last little bit of their horizontal travel, right up almost touching the Orbiter, they veered off to the side, just a wee little bit.

But I do not know that for a fact. I'm just guessing with this one, ok?

Here's a view of things with the outline of the orbiter, to give you a sense of just how close they were with this stuff.

Next item down is going to be the PBK Platform itself, and this thing has some depth of its own, and that's one of the places (there's more than one) where things get hairy, so we're just going to show you the actual platform itself, just the grating, just the stuff you actually walk on, and leave the support framing out of it, ok?

And here's that, with labels, just the part you walk on and nothing else.

And the first thing you should be noticing when you click on that labeled image, to get it full size, is that the hinge line is looking like it's been put in the wrong place, put behind the rear edge of that little flip-up part of things, and that can't be right, can it?

Yes. Yes it can, actually.

The action on this little group of flip-ups is one of the least straightforward, on the whole tower.

Let's see what's going on, by looking at the drawings, ok?

And maybe back up for a minute, and review the whole area, to refresh our view of things in the context of the whole tower.

But that's not the best drawing in the world, despite the fact that I've altered it, in an effort to show what's going on down here, so let's see if we can do better, ok?

And here's a bit of a zoom down into just our area of interest, with another altered drawing (79K14110 mechanical package sheet M-42) which seeks to include the stuff we're seeing in the photograph at the top of this page (which I've added in), while at the same time removing as much clutter as we can (which I've removed), and in this instance, most of the APU Access Platform framing steel at elevation 125'-0", and all of the APS Access Platform framing steel at elevation 112'-0", can be lumped under the heading of "clutter" so I've removed it over on the left side of the drawing. And just to keep things honest, here's the original, unaltered version of M-42, so you have a baseline for proper comparison of what I've done to it, as well as all the information which I removed from it in the interests of clarity, regarding our present, limited, area of interest.

And this drawing is pretty good for showing us why things look they way the they look, because in addition to the Orbiter, which everything wants to come as close to as it possibly can without touching it, we're also getting a good look at the Tail Service Mast, which is also something that all of this steel wants to come as close to as it possibly can, without touching it, too.

We can never forget that the RSS comes pivoting around into all this stuff from several hundred feet away, sailing along like a battleship, but it cannot actually touch anything.

So everything on the RSS has to be built, located, and shaped to keep it from hitting the Space Shuttle. And to keep it from hitting the TSM, too.

And of course the TSM was kind of a battleship in its own right (and that's the barest, thinnest, sliver of the VAB peeking out from behind the near TSM, along the bottom half of it's left side, because this photograph was taken with the MLP, upon which the TSM's sit, sitting in the Park Site, which is just north of the VAB), so we don't want our battleships running in to each other, ok?

On the left side of the drawing I just linked to, we're looking at our platforming "face-on", and on the right side, we're seeing it "edge-on" and in the edge-on view we can see how all of the steel down at elevations 125'-0" and 112'-0" is stepped back, well to the right of our Canister Guide Rail, and for that reason does not really enter in to what we're trying to understand with the photograph at the top of the page, and that's why I've removed it in the face-on view on the left side.

All except for that "hinged stair" that keeps showing up all over the place.

What's up with that thing?

We'll get to it.

I promise.

But for now, let's return to the PBK Access Platform, and that little hinged part of it, with the hinge line looking like it's in the wrong place.

We've been here before. More than once, in fact. But we never finished digging all the way down to the bottom.

Take a look at things, once again, from another point of view, keeping in mind that what's showing in this photograph from the top of Page 32, which we've already seen is the set of platforms over on the Hinge Column side of the RSS, and is therefore opposite hand.

So now we can look again, at a highlighted details drawing of the area, too.

I have been using this general arrangement drawing, to show you where things are located in relation to one another on the tower, but in so doing, I'm misleading you. But not with deliberate intent. You're being mislead because that general-arrangement drawing itself is wrong.

And by looking close, we realize that we've entered, yet again, another one of those areas on the drawings where there are inconsistencies, where there are mistakes. And yes, this is not just to show you things are impossible, as shown on the drawings, right here and right now, but to also show you that this is a real issue, and it occurs in too many places to count, but that you never notice it until you're in there, deeply, trying to build the damn thing, and you keep hitting brick walls and stumbling points, over, and over, and over, and no, it's not some conspiracy, and no, it's not because the people who make this stuff are stupid, it's just the nature of the beast, and it comes with the territory, like it or not, understand it or not, it's just the way things are. Instead, it is a sign. It is an emblem. And it's telling you, whether you want to hear it or not, that you have arrived in a place where humans are taking themselves out to the limits of human ability to do stuff.

This stuff is not for the faint of heart. This is the real deal out here. And each mistake, and each inconsistency, in and of itself, looks simple enough. Looks like something that they should have picked up. And, in and of themselves, as single items, this is true. But there is no single item. There is, instead, a gigantic project. Something that is vastly larger than any single individual who is a part of it. And nobody can know it all. Nobody. Knows. The. Whole. Project... Nobody. And so... you wind up finding things as you go. And you stop, and you send paper to NASA or whomever, requesting clarification, and then those guys go over it, closely, come to a conclusion (which doesn't always have to be perfect either, and which sometimes sets off a cascade of further requests for clarification), and then they send paper back to you, instructing you precisely as to what needs to be done to rectify matters. And this is how the work gets done. And this is what you must learn to do, and do well, if you want to become a part of it.

People who slap at things, people who glance at things, and people who dismiss things with a wave of their hand and a curt, "I don't have time for all that", do not survive out here. They are identified, and culled, just as quickly as the rest of the team can find them and expel them from the project before they wind up hurting somebody, or hurting themselves. Be it financially, or be it physically, or be it in some indirect way, eventually, people who slap at things will always find a way to fuck it all up. And after they've fucked it all up, you can rely on them to start pointing their fingers at everything around them, trying to pin the blame on some body, some thing, any thing, that is not themselves.

And the high-energy people all around them have already had more than enough of it over the course of their lives, and will take action when yet another Dunning-Kruger Poster Child shows up and starts trying to get away with things.

So. Do not think yourself smarter than the project because you found a mistake, ok? This is not the lesson to be learned. This is not the road to take.

Back to our little flip-up platform. On the general arrangement, which is drawing M-42, the small flip-up part of the PBK Platform is shown as having its top elevation, having the level of the top of the grating that your boot heels will be pressing down upon, as the exact same elevation as the rest of the platform. The part that does not flip up or down.

But when we look close, at one of the more-detailed drawings that show these platforms (and there's more than one of them), we start to get an idea that things might not quite be as we first perceived them to be.

But they're not particularly obvious about it, and you find yourself more or less inferring things, although there are are, sprinkled here and there, a few direct indications that things are a little more complicated than they look at first glance.

Step forward in the drawing package to sheet M-46, and things start to come into focus, but even here a mistake has crept into things in the form of a mislabeling of the fixed portion of the PBK Access Platform, where it erroneously gets called the Contingency Access Platform. And although the small flip-up portion of the PBK Access Platform is shown correctly, there's nothing there to actually alert you to the changed circumstances, and for the moment, it could go either way, with the flip-up at the same elevation as the fixed part, or perhaps not.

So we step forward into the drawing package yet again, to sheet M-47, and finally, it becomes pretty clear as to what, exactly, they really wanted here, and as a part of that clarity, we also finally learn why the hinge line that I drew into the photograph looks a little "off" and that's because the small flip-up platform isn't located at the edge of the fixed platform the way every other flip-up on the tower is, but is instead set back in, away from the edge, and pivots around 180° from there, on a pair of lugs that stand up, up above the level of the fixed platform, which forces the flip-up to have it's own set of lugs, which extend out beyond the end of the sensible load-bearing part of the platform, the part that's covered in steel-bar grating like everything else up here is, and for that reason, the hinge line is NOT even with the edge of the load-bearing part of the platform, but instead is farther out, away from it.

Phew!

And then we can step backwards in the drawing package, back to sheet M-43, and finally, buried among a bunch of revision clouds telling us about handrail and safety chain mumbo jumbo, stealthily hidden in plain sight, the whole thing suddenly springs into sharp focus.

That goddamned little flip-up platform has grating, the stuff you walk on, on both sides! Top AND bottom. And the only reason a thing like that could ever be, is because this thing got walked on, when it was extended, in its 'service' position, and it also got walked on, when it was folded back, in its 'stowed' position, and for any of that to work, the thing couldn't be out on the far edge of the fixed platforming, and not only that, if it was somehow rigged up so that it could be out on the far edge of the fixed platforming, then it would interfere with the little fold-down double-flip which, of course, is our Contingency Platform.

Ye gods!

What a nightmare!

And then...

...and then, the Sly Little Note.

Which is telling us, without ever coming out and saying so directly, that these platforms will never be extended simultaneously.

You either use the PBK Flip-up, or you use the Contingency Platform Flip-up, but you never use them together at the same time, because if you try to do that, the PBK Flip completely blocks all access to the Contingency Flip which is sitting there directly underneath it. And you slap yourself upside the head and say to yourself, "Of course! Of course the goddamned thing couldn't be used that way! Why did I never notice that before? WHY?"

Lovely, eh?

Which means, and I cannot stress the deviousness of this enough, that these things get shown, all over the drawings, in an impossible configuration. In a configuration that could never be used as shown.

And you look at these things. For literal years. And not you, and not anybody ever notices it.

Sitting right there in plain sight.

And yeah, sometimes this stuff is a certified bitch.

And yeah, I'm running you through this maze as another aspect of sharing my world with you, taking you down into its deepest levels, letting you learn what it was really like out in the field trailers, and up on the towers, as this stuff was being transformed from lines on paper to cold hard steel, and questions would come up, and you'd start asking those questions, start asking such simple questions, start asking "How the hell do we actually direct our fabricator to build this thing and then get it installed on the tower?" and your people, and the prime contractor's people, and the other subcontractor's people, and the craft-labor people, and the safety people, and the QA people, and the union people, and NASA's people, and who-knows-who-else would all get into the act because everything affected everybody to greater or lesser degrees and oftentimes it was hard to tell who and by how-much. And at first, it's just casual conversation over a drawing table or up on the iron, and maybe that would put it to bed, then and there, but maybe it wouldn't, and differing parties would come to differing conclusions and opinions of things, and it might or might not involve somebody's time and money, and it could sometimes take on a fully-independent life of its own, and all you could do would be to keep your eyes wide-open, hold on tight, and ride it, wherever it might wind up taking you. And never forget, the people involved, the people drawing differing conclusions, were the best in the business. And yet... questions.

This is by far not the best example of this sort of thing, but it's at least illustrative-enough of the process. The process of digging. The process of getting to the bottom of things. And there could be personal visits, phone calls, paper flying back and forth, and meetings of every possible type, be it a casual "Oh, by the way," conversation up on high steel with a foreman and his 4-man gang of ironworkers, all the way up to very formal, and scary, holding the potential for possible outrageously-expensive consequences, sit-downs around the Big Table with high-ranking representatives from NASA on down, and all manner of other group communication sessions, and in the end, the thing would get built, but trust me here, there were times...

...times when you harbored serious doubts about any of it coming together in the real world.

And as regards our present visit with a complicated set of fixed and flip-up platforms with mutually-exclusive operational modes...

...it turns out that the ironworkers, and the pipefitters, and the electricians, and the painters, and every goddamned body in the world, likes them better when they're in their "impossible" configuration, with all three flip-ups in the flipped-down position all at the same time, and by god that's the way you find them, every time you return to the tower.

And why might everybody like them better in "impossible" mode?

And it turns out to be a use case which the project's original design/engineering people never in their lives imagined that their platforms might be put to.

That lower double-flip, the Contingency Platform part of things, makes a perfect shelf to hang things on. Like it was made to order or something.

It's too perfect to not use.

And so they use it.

And if it's "wrong," nobody gives a shit.

"We're using it."

And so they do. Exactly that.

And later on some distant day in the future, when the customer takes possession, well then...

Let the customer do whatever the hell they want to with 'em.

Not our problem.

And, sure enough, now we come down one small step lower, on our photograph, and guess what?

There it sits in all its glory, in "impossible" mode.

Being used as a shelf.

And in the photograph, clearly (now that finally, at long last, we know what the hell it is that we're actually looking at), we can see that somebody's got one end of their pickboard sitting directly on top of that lower "Contingency Platform" part of things.

Of course.

Of course they do.

How could they not?

It's too perfect.

It's made to order.

Alright then, we've finally reached the bottom of things.

Are we done yet?

Nope.

We're not done yet.

Sigh.

Remember that "Hinged Stair" from a little while ago?

Where I said "We'll get to it. I promise."

Well, now we're going to be getting to it.

And you look at the photograph at the top of the page, or the cropped version of it to help keep things focused, and you've got to be wondering to yourself, "What hinged stair?"

And right here, the ever-so-thin slivers and slices get even thinner.

But they're there, so let's give 'em a look.

And, just to refamiliarize you with this thing, I'm going to remind you that we've been here before, too, and we've seen this thing before too, and it has an actual name, and its actual name is the Hinged TSM Access Stair.

This stair starts out with its top landing at 125'-0", which is part of all of the rest of the APU Access Platform framing down there, and that top landing is supported by a triangle of three vertical members coming down from above, and the one that's farthest forward, farthest away from the back of the RSS at Column Line A and closest to the Space Shuttle's wing when the RSS is mated, is even with, and can be considered a part of (even though it's not), the forwardmost edge of the fixed portions of the PBK Access Platform framing at elevation 133'-9" farthest out there beyond Column Line C.

And here's all that right here, along with the PBK Fixed Platform Steel, and the Monorail Support Steel up above that, so you can start to get a feel for this stuff as regards its elevations, as well as regards how far forward it is, out away from the main body of the RSS, beyond Column Line C.

And then here it is again, in the only drawing that actually shows the stair extending out beyond the forwardmost margin of the PBK Access Platform fixed framing steel up above it so you can see the overhang, but we're looking at the Hinge Column side of things, so it's the other stair, and we're looking at it from behind, so yeah, you need to be mindful of all that, ok?

And then, before I show it highlighted on the photograph, let's look at the structural drawing for it, sheet S-47, and see what's actually visible so as we'll understand what we're seeing, and, for you detail people, please take note of the fact that the intermediate handrail post does not show up in the photograph, because it's around that corner in the horizontal handrail pipes, hidden from sight by the smallest margin imaginable.

And now, finally, here it is, on the cropped photograph.

And of course, now that we know what we know, it all seems so easy. Like... duh... how could it be anything else? Right?

And then we go back to the original photograph.

And see if we can do the whole thing, top to bottom, without help, without a set of training wheels.

And yeah, it's doable, but it's not particularly straightforward, easy, or simple.

And I'll leave it as an exercise for the student to locate, in the photograph, the horizontal top surfaces of the framing steel for the fixed portion of the PBK Access Platform at elevation 133'-9", and the diagonal double-angle framing which supports it and heads upward on a slight angle to the steel that's holding up the Monorail at elevation 144'-6¾", and the top surfaces of that steel, also at 144'-6¾", and the diagonals that go up from there, and tie the whole thing back to the heavy iron of the RSS on Column Line C, with an upper on-center workpoint at 150'-6¾". And then, maybe after you've found all of that (and yes, it's there), maybe start looking for lighter stuff up in this area, too.

There's plenty there.

That should be more than enough to keep anybody busy for a good while, right?

Happy hunting!

And for those of you who were warned off, with an admonition of some tough going ahead, followed by my saying I'd give you some kind of notice, farther down, maybe in boldface type, that it's safe to come back outside and play in the yard again, well then, ok.

It's safe to come back outside and play in the yard again.

So now that we've finally put that little ordeal behind us, let's move along with things, and we'll get ourselves a few more identifications of other stuff, not part of the nightmare complexity of what runs down the face of the RSS over there on the Column Line 7 side of things, which is also visible in the photograph, and we'll start with the RSS Main Floor Steel at 135'-7" which is one of our cardinal locations, one of our main centers of gravity for this whole series of photo essays, and which also, once we know its precise boundary over on its left side, we will then be able to much-better recognize and identify all of the stuff down there below it.

Here it is, here, RSS/PCR Main Floor at elevation 135'-7".

So ok, so we've done everything up from the Main Floor, so let's head down from here, and see what we can see.

May as well start with the Canister Access Platform at elevation 125'-0", which we've already met, and which is sticking out there in plain sight, not really covered up or mixed up with any of the other stuff that's down here.

Of note with this thing as you're seeing it here, is that it's nearly transparent, with our near-vertical point of view, and the near-perfect alignment of the steel-grating bearing bars (which have a sensible vertical dimension, as opposed to the banding bars which do not), and as a result, we're looking right on through it as if it was a sheet of glass laid down on top of its support frame, which is clearly visible through the "transparency" of the grating, and below that, the APS Servicing Platform, elevation 112'-0", Floor (itself, partially "transparent") including the curved Orbiter Mold Line which defines its perimeter, and beyond that, the gray concrete of the Pad Deck, far below.

We'll let this be another small example of the scary weirdness of steel-bar grating insofar as that, despite the fact that it would easily stop an anvil dropped from the top of a skyscraper, it sure as hell does not look that way when viewed just-so, and when you're looking through it, it can be quite unsettling before you get fully used to it and begin to fully trust it, in a reflexively-unconscious back-of-the-mind way.

Elsewhere, still at the APU Service Platform area at elevation 125', we can also see a few slivers of the Compressible Bumpers which define the Orbiter Mold line at this level, as well as just a wee little bit of a very nondescript pair of Vehicle Access Platforms which provide access up in the sort of crevice between the OMS Pods and the Space Shuttle's Tail in this area, and I may as well point them out to you now, as well as point out the fact that they are supposed to have a set of their own Compressible Bumpers, but on the day I took my photograph, for reasons unknown, those bumpers were not installed, and instead, all you're seeing is the bare steel of the platforms, keeping in mind, again, that from where you're looking, the steel-bar grating on top of these things is effectively transparent, which is actually kind of nice, as it lets you see their actual steel framework really well, but maybe not so nice as it also lets you see whatever is beneath them, which can be a source of confusion if you let it.

And speaking of confusion, once we get below 125'-0", things get all tangled up again, with a main floor elevation at 112'-0", a pair of pivoting OMS/RCS Hypergol Access Platforms perched on top of that, and then another set of folding OMS Access Platforms farther up at elevation 114'-7", and then if that's not enough, yet another scaffoldboard laying on top of a bunch of that, and all the rest of the usual suspects with handrails and lines and ropes and whoknowswhat, things being see-through that you don't want to be see-through, and other things not being see-through, that you wish they were see-through, and you've already visited this stuff on Page 24 in Lower Hypergol World anyway, and...

...nah.

Some other time, maybe.