The Construction of Space Shuttle Launch Complex 39-B

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

Ok.

Now we're up on the Pad Deck with our OAA, and we've attached the Environmental Chamber to the end of the arm which will be coming ever-so-close-to, but not quite touching, the side of the Orbiter, and we're up on top of the Arm, putting the Lifting Gear together, and we're not very far away at all from hanging this thing on the side of the FSS, one hundred and fifty feet above the Crawlerway concrete that you see everybody and everything standing on top of in our photograph.

This is an exceedingly-similar procedure to hanging the GOX Arm, so maybe go back to Page 66 if you'd like, to review some of what's going on with what Union Ironworkers have to do in order to get this thing rigged, prior to Lifting it.

And I've already told you I do not have a proper set of drawings for the OAA itself, or the Environmental Chamber which hangs off of the end of it, but I do have a few things which might be of use, and we've seen some of them before, and we're gonna try to focus mostly on the Environmental Chamber first, but since it's part of the Arm... well... you're gonna get Arm stuff too, ok?

Page 71, which we just left, included a link to a (less than fully wonderful) general arrangement isometric view on 79K24048 sheet M-326 showing us the Orbiter Access Arm in its working position, extended, but with the RSS in its Mated position, too.

And this is what they would be dealing with every single time there was an Orbiter on the Pad, with the RSS swung around and Mated to it, while they were doing whatever pre-launch work they might need to be doing (and oh good lordy gollamighty was there ever a lot of that kind of work which had to be done for every single launch). Which means it was by far the most common configuration, but it's not the one you are used to seeing, because what you are used to seeing, is the Space Shuttle sitting there on the Pad with the RSS rolled BACK, completely out of the way, in the de-mate position, with or without the OAA fully extended in its service position with the Environmental Chamber butt up (but not quite touching) against the Orbiter. And nobody ever considers stuff like this. Nobody ever thinks about it. They just take it for granted, that, ok, there sits the Space Shuttle, in plain sight, with that great goddamned big steel contraption, whatever the hell it is, over there on the side of the photograph, or the video, or whatever, out of the way, and who cares what it is, or what it's doing over there, and ok, fine, whatever.

And nobody ever gives the slightest consideration to what things might be like, when the gigantic steel contraption was somehow wrapped around the Space Shuttle, completely blocking it from view, and hell, nobody even knows that a thing like that is even possible.

They never see it. Nobody ever shows it to 'em that way, because the Sexy Factor falls waaay off when the Shuttle is unseeable, and who gives a shit about gigantic steel contraptions anyway?

Right?

So for the vast majority of the population who even looks at pictures of the Space Shuttle at all (And how many people do you know, who could not possibly care less about it?), there is zero sensible awareness of what's going on with the OAA when the RSS is mated to the goddamned thing, as must it be, for the overwhelming preponderance of the time we're out on the Pad, preparing things for launch.

And I mentioned on Page 71 about how the OAA is "crammed in underneath" The RCS Room when the RSS is mated to the Orbiter. And in addition to that, it's not quite banging into the fucked-up Antenna Access Platform as it does so, but it's close, and...

It's pretty fucking tight in there, and it's near-impossible to properly visualize this stuff, but way back on Page 30 I took my best swing at it anyway, while I was fleshing out further details and interestingness on the Hated Antenna Access Platform, and I'm gonna link you back to some of the relevant graphics I cooked up in order to try to show you how this crap all fits together once again, because it's time to Hang The OAA, and the time to gain proper understanding of the OAA is...

...now.

And all this happens with the OAA in its extended position, and by now you may or may not have noticed that, holy shit, the stupid OAA can NOT be retracted back against the FSS, out of the way, when the RSS is mated to the Orbiter!

There's nowhere over there for it to go when the RSS is in Mated Position.

It HAS to be extended.

All crammed in there underneath the RCS Room, slap against the side of the Antenna Access Platform.

Take it or leave it, we're not asking you, we're telling you.

So ok, so now that we're sort of up to speed with this ever so sneaky and hard-to-visualize aspect to the goddamned OAA, let's see if we can try to come up with something to, sort of, let us see how all that works, ok?

We'll start by returning to 79K24048 sheet M-326, but this time it's marked up to show the cutaway loud and clear, with the OAA down there underneath the RCS Room, as well as the fact that they misrendered the Antenna Access Platform and Left Side Seal Panel in relationship to the OAA (and no, I do not know if the misrender is because those two items are wrong, or if the whole ARM is wrong, or maybe some combination of the two things working against us together).

Then we'll head all the way back to Page 30 to the part where I hit this stuff VERY glancingly, and pull up a couple of things I needed to show you at that time, but did not bother to further elaborate on at the time, mostly because you weren't ready for it back then, but also because I was going on and on about Compressible Bumpers, as part of explaining this whole area, inside the RCS Room, and beneath it on the Antenna Access Platform, and... at the time, that was way more than enough, and I let it go.

First, 79K14110 sheet M-45, to see some renderings of the OAA in there with the RSS more or less surrounding it, when it's mated to the Orbiter, complete with a couple of views which include the Orbiter itself, to help understand the overall orientation and interrelationships between all the main players.

And this drawing is not an easy read, ok?

In fact, it's a difficult bastard to read, and will leave you feeling like you know less, after looking at it.

We can start trying to figure out M-45 by looking over on the left side, just a little bit above center, at "Plan At RCS Room Floor El. 212'-2", which is looking straight down on top of the whole Orbiter Access Arm, from FSS to Crew Hatch on the Orbiter, and over where I've blue-highlighted the Environmental Chamber, it's giving us Column Lines, and those Column Lines are for the RSS, which is of course mated to the Orbiter in this plan view.

So stop, and give Plan At RCS Room Floor some consideration, ok?

The OAA is showing, and the framing steel which lives on those Column Lines is also being shown, and in so doing, they're telling us that this framing steel, is sitting right there, just above the OAA. We're not hitting the OAA with any of this steel, but you're for sure as hell not going to be standing on top of the OAA where they're showing you this steel, because... hell, there's not nearly enough room to even lay down, on top of the OAA in there underneath that steel. It's CLOSE. Very very close. And they're further telling you that if you go just a wee little bit towards RSS Column Line A with your OAA, trying to swing it around toward its retracted position, while the RSS is mated, you will be dealing with more steel, what they're calling the "RSS Roof", and that stuff is even lower.

So ok. So maybe they weren't being quite as explicit with things as we'd like them to be, but they're still telling us, and it's our responsibility to understand what we're being told, and not theirs, ok? If you wanna come out here and run with these dogs, then you had better be good and ready to keep up with these dogs. 'Cause they've all got work to do, and none of 'em are gonna be stopping what they're doing, to wait for you to catch up. And that's just the way it is, and that's just the way it has to be.

Additional consideration of "Plan At RCS Room Floor..." tells us that the OAA, when it's in its Service Position, when it's flush up against the Orbiter so people can crawl through the Hatch, it's coming at the Orbiter at an angle.

It's not square with everything else up here, ok?

And they even tell us the angle.

In Degrees and Minutes.

And if you don't know what Minutes of Arc are, then maybe it's time you learned, hmm?

The OAA sticks out away from the FSS at an ever-so-precisely-specified 76° 36' angle, swinging counterclockwise off of the true north-south alignment of the RSS when it's mated, from a pivot point which is 5'-6" east of the centerline of the Hinge Column, and 34'-6½" north of it.

And that's that. And with that we've got everything we'll ever need to let us know where this thing is, when we're building the rest of our Launch Pad around it.

The Orbiter, sitting on the MLP, runs the show.

And the OAA is built to the Orbiter.

And everything else in this area is built to the OAA.

And that's that.

And of course that's not that, at all, because "Plan At RCS Room Floor..." is flawed, and it's flawed twice. Once because of a very unfortunate lack of quality with this reproduction of the original drawing, which I am forced into working with, because... there is no other version of this thing that I have ever been made aware of. And the second "flaw" is the drawing itself, which is not fully accurate, and is downright misleading in a few key locations, so... we're going to have to step very carefully around here, and I'm going to try to bring this drawing back, as much as I think I can, while retaining faithfulness to a created on paper (which we sure as hell don't even have, remember) version of this thing, and... oh boy, this oughtta be fun, eh?

We'll start by giving you the bare unrectified, unannotated version of 79K14110 sheet M-45 straight off of the original digital material which I have been so astoundingly fortunate as to come into possession of, and which, of course, is what initially set off the whole saga of creating this narrative, in the first place.

And yeah, that thing's not the best, eh?

And before we go any further, we need to know why this drawing was created in the first place, and it was very definitely not created to help anybody out with the Orbiter Access Arm, and instead it was created so as they could put a ladder in one of the daffiest places imaginable, to give them contingency access to a Panel on the Orbiter that provided a Quick Disconnect (QD, and if you see "QD" anywhere else in these drawings, that's what it stands for) interface for the Water Coolant System.

And "Water Coolant" crops up in more than one place in the Orbiter. One of the places it's used is for the APU's, and you can read up on that end of things here, in Space Shuttle Auxiliary Propulsion System Design Study, which was written way back in 1972, and tells us how they decided against liquid hydrogen in favor of water, for this application.

But I'm pretty sure that's all in the back end of the Orbiter with the Water Spray Boiler System.

Up front, where the Crew Cabin is, you get Environmental Control Life Support System (ECLSS) stuff, and some of that uses water too, and I'm pretty sure our Water Coolant System as it relates to our bizarre Ladder which we might find ourselves needing to use, would be a part of this end of things, and you can read about it here if you'd like.

Here's our "Water Service Panel" on one of the pdf files that were once upon a time freely available from NASA, but at some point, somebody decided they shouldn't let us see this stuff, but by then, the horse was well and truly out of the barn, and you can find these in a variety of places on the internet, in addition to right here, if you look for them. I pulled mine down directly from JSC, before the screwed the lid down on it, and was smart enough to save 'em to my computer when I did, so... ok.

And here's some more, which I've decided not to mark up, but which include a few tidbits of interest for those who would like to know a little more about this stuff. 210b Forward fuselage coolant/air revitalization components 1 shows us the front end of things. And 210c Mid- and aft fuselage coolant system, shows 'em to us farther back, behind the Crew Cabin. Dig in. Have fun with it. Come back here when you're done, ok?

The fact that the OAA is in there at all is merest happenstance. This thing could have been anywhere. But it wasn't. And instead, it was in nasty, near-impossible-to-get-to location on the Orbiter when the RSS was mated to it. And how all of that came to be, I'm sure I'll never know. It just is, and we'll just have to deal with it, as is.

And before we're done with this, we'll know all about that Ladder, but right this minute our attention is focused on "Plan At RCS Room Floor..." on M-45, because it shows us stuff about how the Orbiter Access Arm works that we do not get to see anywhere else, except that it's flawed, and I've got to fix the damn thing, and even the fixes are a pain in the ass, because I must include other drawings which show us what's going on here well enough for me to do the damn fix, ok?

And we're gonna make a couple of fairly intricate loops as we go along, so maybe get ready for that too, ok?

Here's 79K14110 sheet M-45 with just those areas we're interested in for the moment, marked up to help you understand what they're trying to show you, and if this is not the worst drawing in all of 79K14110 as far as poor-quality of workmanship goes, it's pretty damn close.

And right now, all we give a shit about is found in the top left quadrant of the drawing, mostly involving Plan At RCS Room Floor El. 212'-2" but also, just a little bit, involving Partial Plan At El. 198'-7½" & 212'-2" which is just above "Plan At RCS Room Floor..."

And the reproduction is faded to invisibility, and the original drafting is misleading, and oh boy, here we go.

The Arm. The stupid Orbiter Access Arm. What's going on with that Arm? That what we came here to learn about, isn't it?

Yes. Yes it is.

But it's stuffed up in there in a hole, with cold hard Rotating Service Structure steel threatening it from all sides, and we need to understand how it all fits together in there.

And unless I specifically indicate otherwise, everything that follows below is talking about JUST "Partial Plan" and "Doctored-Up Plan" on M-45 repaired Marked Up 1. We'll move on to the rest of the drawing soon enough, but not right now, ok?

On the bare original M-45, "Plan At RCS Room Floor..." contains a bad Orbiter Mold Line. And a lot of it is faded either beyond recognition or all the way out to invisibility. And the way some of the lines that do show were handled is exceedingly suboptimal, and a bunch of that stuff is very very misleading as a result of it.

So we've got a lot to be dealing with, just up in this top left corner of M-45, all by itself.

Once again:

M-45 bare original.

M-45 as you first saw it back on Page 30.

M-45 at its present state of reconstruction and marking up.

Bounce back and forth between them to understand what's been done in the name of clarification. Give the altered version a good close squinting at, because some of what I did to it is... non-obvious. Which means you gotta squint at the previous versions too, in order to catch all the changes to the eency-weency niggly little stuff that's going on here. Top left quadrant only. For now.

In the unrepaired versions, it's near-impossible to understand the actual steel they're trying to show you. A lot of it simply does not make sense, both because of degraded material that you can't see clearly, or at all, and poorly-done renderings of the stuff that you can see.

The bottom-right corner of the RCS Room, down where the Environmental Chamber looks like it's just maybe touching a column, makes no sense at all. What's going on where the line from "Access Ladder Attached..." cuts across things along Column Line D? What's that murky crap over there to the left of that "Access Ladder..." line, just below the Column Line D Location Line? And if you look at what I've done to it in the repaired version, closely, it still really doesn't make enough sense, so we have to go back to the Structural Drawing that we built the damn thing to, to see what's going on down there, in just that one little corner of things.

Which I've ever-so-kindly marked up for you on 79K14110 sheet S-59, and what they're trying to show you down there on M-45 is the front side of the RCS Room between the Corner Column at Line D-3.4 and the vertical door jamb steel for the big Roll-up Door on the front of the RCS Room. And it's a very small detail, but it's emblematic of things, and somebody drew some goddamned lines on M-45, and it's never a good idea to be looking at lines on engineering drawings, having no idea what they're there for, or what they might represent, without taking the time to get to the bottom of things, so... ok. Now we know.

And while we're at it here, 79K14110 sheet S-59, Elevation 'A', which is part of "Elevations RCS Room", is the only place where we'll ever find out what's going on up here in the vicinity of elevation 212' and below, at the intersection of Column Line C and 3.4, and they take us from Elevation 'A', down to Detail 'D', along the lower left margin of the drawing, to make sure we really know what's going on here, and I can see why the poor mechanical guy who had to draw M-45 threw up his hands in despair, and just sort of bodged it, hoping it would pass inspection, and it did.

And what's going on down at that location consists in a great-goddamned-big vertical W36x194 column (which we've already met no end of times previously, since it's RSS Primary Framing, and we are expected to be completely familiar with it, and you may admire its Line 4.6 opposite-hand counterpart's lower end, seventy-five some odd feet below, with nothing whatsoever beneath it except for a gut-churning free drop to the Pad Deck, in the lead photograph at the top of Page 54), which is coming up underneath a plenty big enough horizontal W21x57 beam, which itself has another vertical member on top of it, and that vertical W12x53 column isn't even on center with the vertical W36 column groaning down there underneath everything, holding it all up, and.. that's a pretty whack connection right there, boys and girls, and the mechanical draftsman had zero interest in all this goof-ass structural gobbledygook anyway, and...

You and I get to use this thing... whether we want to or not... and...

Onward.

Over to where the Environmental Chamber runs beneath all that framing and platforming steel, which is a place where things are particularly gubbed up.

Fucking thing don't make a lick of sense.

The Orbiter Mold Line on the unrepaired original is all horsed up, and down where it needs to be tucking back in, as it closes in on Column Line D, somebody just kind of said, "Fuckit" and decided they did not need to finish the curve, and that goddamned thing is extraordinarily misleading, and you find yourself wondering, "Is it platform steel? Is it the Orbiter? Is it framing steel? What the hell is that thing, anyway?"

The Orbiter Mold Line you see on the repaired version of M-45, down where it closes in on Column Line D, was cut from 79K14110 sheet S-41, resized to match its new background, and pasted in there.

And what's up with the flip-up platforms? Are they up? Are they down? Both at the same time? Whu?

And then there's the framing steel that lives behind the hinge line of the flip-ups, tying back to the heavier iron on Line 3.4. That's a goddamned mess, too.

And back farther away from Line D, back where it's solid floor steel without any flip-ups, they've put a member in there all nice and neat, and then, just to confuse the hell out of everybody, they put an Orbiter Dimension Line "Z_o - 400" right next to the location line for Column Line C, and dammit, that's not a steel beam in there, no matter how much it might look like one.

And while we're on the subject of lines, I may as well take this opportunity to draw your attention (presuming it hasn't already jumped out of the tall grass directly at you, on its own) to the fact that the business of rigorously following all the standard conventions involving the use of double-dash, single-dash, repeating-dash, and unbroken lines has been cast overboard in this blighted little corner of the universe where sometimes they do, and sometimes they don't, and it almost looks as if they decided to do this whole area in either phantom (double-dash) or center (single-dash) lines, except for the stupid Ladder and the Panel on the Orbiter, and that doesn't make any sense, and I'm not even going to bother pointing any of it out, above and beyond the mere fact of writing the words in this paragraph. Fuckit. And it may or may not have been done better and/or correctly on the fucked-up paper-original, and it looks vaguely as if they might have tried, but that visual information has gone the way of the dinosaurs, never to return, and I just filled it all in any old whichaway, and I've got a few labels in there to guide you along through this very dark forest and you guys are big girls, and big boys, and I have every confidence in you, and you'll be fine, goddamnit.

And there's also nothing at all about the rendering of the Environmental Chamber that might cause you to believe it's underneath all of that steel and mess, anyway. Nothing.

And we'll ice this cake by going up to "Partial Plan" and looking at the stupid Ladder, which is done in hard line, even though it's down there attached to the underside of that flip-up platform it lives on... and what the fuck are we doing with a Ladder of all goof-ass things, welded on to the bottom side of a goddamned flip-up platform anyway?

Not now. Stick around and we'll get to it. I promise. But not now. We've got more than enough on our hands as it is, right now, ok?

And I tried to label, and mark, and highlight, and fill in, and erase, and...

You do not want to know how much time and effort was expended in making sense of this crap in the first place, and then correcting the motherfucker in the second place. Gah.

And there should definitely be a sense of familiarity with what we're looking at now, because we've been here before with this narrative.

Twice, even.

The lead photograph on Page 29 gave us an excellent look at the Orbiter Mold Line which cuts a large rounded-off hole in the RCS Room Floor at our good friend, Elevation 212'-2".

And the lead photograph on Page 30 showed us even more, from underneath, in this exact same area.

And the goddamned OAA is supposed to be fitting into this stuff... somewhere, and god damn it, we're gonna learn exactly where, before we're done with this, no matter how fucked-up 79K14110 sheet M-45 might actually be.

Let us now turn our attentions elsewhere on this marvel of a drawing. Let us now give the lower left quadrant of M-45 a look, now that we've established at least a sort of half-assed understanding of the steel structure that fills the spaces just above the OAA, as depicted in Plan At Elevation 212...

Oh boy, more fun!

And without further preamble, the Second Doctored Up Version of 79K14110 sheet M-45. M-45 The Second.

Drop down below "Plan At RCS Room Floor...", and you get "Elevation Looking South" in the far bottom left corner of the drawing, and right next to it, to the right, "Elevation Looking East", and these two Elevations take up the entire bottom left quadrant of the drawing, and that quadrant is our area of interest at this time, and it's plenty more than enough, all by itself, let me assure you.

Go look at that stuff, ok? Now, please. Don't even bother trying to make sense of it. I mean, yeah, there's the Orbiter, and a bunch of steel and stuff, and a bunch of words and arrows, but just leave that alone, ok? We're gonna do it, but first, just give it the old once-over so as you're at least aware of our general location and point(s) of view. Click the link and go there, take a little time to just sort of... admire it, and then come back here when you're done.

Thank you.

And in the meantime, while you were away, I've decided to upgrade this drawing from being one of the worst in 79K14110, to being the very worst. Hooray!

We're trying to learn about clearances, for all that crap which surrounds the OAA when the RSS is mated to the Orbiter (And please do not forget about the Hinged Left Guide Column, which we met back on Page 66, and which you are presumed fully cognizant of and fully familiar with, and no, none of that shows on M-45, so... mind, ok?)

And here's 79K24048 sheet S-224 again, just to refresh your memory of where that Hinged Guide Column fits in to its surroundings right next to the OAA, but try as you might, you will never find the Canister Guide Rail or the Big W36x194 which I've had to include and label on M-45, and it's almost like they wanted to hide that shit, across several different drawing packages, but for the life of me, I'll never know why.

Ok. We need to stop here. I've just shown you the second doctored-up version of M-45, and it's riddled with dimensions, a lot of which were never on the original, and I did not have room on the drawing to tell you where I got all those dimensions, and it's getting out of hand, and who's to say I'm not just making this shit up, so I'm gonna give you a list of where it all came from, so as you can check my work, to verify I'm not just making shit up, and even just that is gonna be a giant fucking pain in the ass, because some of the dimensions had to be derived, and I also for sure as fuck do not trust all of them equally, and...

Fuckit.

Here we go.

Working more or less high to low in our Quadrant of the Damned on M-45...

Bottom of W21x57 El. 210'-3¼" on M-45 The Second, is derived from 79K14110 sheet S-41, RCS Room Floor Framing Plan @ Elevation 212'-2", which tells us there's a member running from Line B to Line D on Line 3.4 which is a W21x57. 79K14110 sheet S-59, Elevation A (which is cut from 79K14110 sheet S-43) is showing us the Line 3.4 side of the RCS Room, and agrees that there's a "W21" at Floor Level in the RCS Room on Line 3.4, at Line C (which is what we're seeing on M-45 "Elevation Looking South" even though it does not specifically tell us that), and tells us to go to Detail D on that same drawing, S-59 to see what's happening with the "W21" at Line C-3.4, and that Detail D tells us there's a W36 column coming up vertically beneath our W21, and it also tells us T.O.S. (Top Of Steel) of the horizontal W21 beam is at elevation 212'-0¼". Ok. From there our Manual of Steel Construction tells us that a W21x57 is exactly 21" deep (which is rarely the case for members specified by inches of depth, if you were wondering), and when we come down exactly 21 inches from 212'-0¼", we wind up at 210'-3¼", and ok, there you go, our first derived elevation, tra la la. Check it yourself, if you don't trust me (and you should, and you should strive to develop this as a habit, if you ever Get Into the Business, and you don't do it because you don't like me or you don't trust me, you do it because it'll keep you out of one HELL of a lot of trouble at some unknowable point down the line, in the future, and Future You will thank Today You profusely for developing this life-saving habit, ok?).

Top of OAA El. 209'-6" is given elsewhere on M-45, and we'll get to that side of the drawing, but not right this minute, although we'll happily use what we're given as the elevation for the top of the OAA, and of course, the only part of the OAA we're really interested in, is the Environmental Chamber, so if you see me say "OAA" kind of don't forget that it's the Environmental Chamber that's our immediate Subject of Interest, and the rest of the Arm, can be ignored for the most part.

Which, also of course, allows us to derive 0'-9¼" Headroom Clearance Above OAA, as the RSS is grandly steaming in toward us, coming in at us around from the side like a battleship, with the bottom flange of our W21 passing directly above the Environmental Chamber as it does so, which sounds all well and good for room enough, except that it's not, and What This Part of the Drawing Giveth, That Part of the Drawing Taketh Away, and we'll get there soon enough, ok?

And 198'-8⅜" bottom of OAA turns out to be a rat bastard, and as far as I've been able to tell so far, they never do give it to us directly, and instead...

We find ourselves having to work indirectly with things, to an unknown degree, and we're gonna be heading over to 79K14110 sheet M-70 real soon now, in just a couple of more paragraphs, where the tops of the Left Side Seal Panel and the Left Canister Guide Rail come together right next to the Big W36x194 Column at the far end of the Antenna Access Platform where that annoyingly-complicated Flip-up Platform tucks in to the top of the Left Side Seal Panel, and I didn't bother giving you clearance between the bottom of the OAA and the Antenna Access Platform because the OAA doesn't quite make it that far, so there's no actual overlap, but with the Canister Guide Rail, there is some overlap, and careful there Lou, don't go swinging the OAA into that W36x194 column while you're at it, ok?

And the Big W36 in particular, is close. We don't quite hit it, but we come... close. Very very close. Or actually, I should be saying, "It doesn't hit us," because the poor OAA is already fully extended, up against the side of the Orbiter, and it's the RSS that's in motion here, W36 column and all, and if push was to somehow come to shove, the OAA has nowhere to go, and every time we mate the RSS to the Orbiter it's truth-or-consequences time with that W36 and the OAA, and... like I just said... careful there, Lou, ok?

And as we're having to deal with all of that crap, we notice, "Oh by the way," that in 79K14110 sheet M-70, Section D, which is cut from 79K14110 sheet M-68 (and yeah, I had to repair and rebuild that goddamned thing too), they've ever-so-casually dropped in a little note that says, "Swing Arm Clearance X_o 559.62", and ah, shit, now we gotta go back to the fucked-up Orbiter Coordinate System and see if we can convert that into the feet and inches system we're using to build the stupid tower to, and...

Hairy enough for you yet?

And at no point does anybody ever tell you what "clearance" actually means in this instance, and is it the lower edge of the actual steel (or aluminum, or some bracket, or...?) of the OAA's Environmental Chamber, or is it something which contains within itself some margin or other, which means we might have just an extra smidgen or two of squeak room for this thing to not hit what's underneath it over here, and...

Giant pain in the ass is all it'll ever be, and it's also all we're ever gonna get, so... grin and bear it, I guess.

And if you're wondering why I might be going to such extraordinary lengths to walk you through this unpleasant district of The Dark Forest... well... a little while ago I mentioned "if you ever Get Into the Business," and this is exactly the kind of shit you're going to be finding yourself having to deal with, and you're thinking, "Ok, so what," except that your thinking is incomplete, and what we're dealing with here, In The Business, can turn out to be the loss of eye-wateringly large sums of money, in addition to the continuance of your own employment coming to an abrupt end, and it doesn't really matter if it's lines on paper, or lines on a screen, or if it's two-dimensional, or three-dimensional, and you can rotate it around and look at it from all angles when it's 3-D, but that doesn't matter, because... it's just lines, and the paper, or the screen, will very obediently put whatever line somebody dictated it put, at whatever location that pleased them, and there's always going to be some asshole with more power than intelligence (or morals), telling you to, "Make it like the drawing shows," and if the miserable sonofabitch is making demands like that because he's crooked, and knows full-well that it's impossible, as-shown, but he also knows it's gonna cost him a bundle of money to make it right, then he's gonna lean into it, with every bit of strength he's got, and YOU had better be on top of this shit to a degree where you can take the stick he's coming after you with, snatch it out of his hand, and then turn it around and shove it up his ass, and break it off up there, and the only way to be able to do that is to be on top of this shit, and there's this guy's set of drawings, and that guy's set of drawings, and some other guy's set of drawings, and they all sure do look pretty, and all the lines on all the drawings close up nice and neat, but yet somehow, the wholeness of the thing fails to pass the Sense Test, and it's up to you to keep people with sticks in their hands from being able to do to you what they want to do, and...

Are we getting the idea here yet?

They're playing hardball, and they're not kidding, and they will hurt you if you let them, so you must be able to integrate different things from different systems, or even the same system, the hard way, the old-fashioned way, and in the process of integrating things, it goddamned better well motherfucking fit, and be buildable, or...

...you're gonna be looking for a new job, and your former company is going to be looking for people to purchase their assets in Bankruptcy Court, and no, I'm NOT exaggerating, not to the slightest degree, because I've seen it, with my own eyes, and you never know where the next Horseshit Event is gonna be coming from, so you must, at all times, know everything about the situation you're dealing with, good and bad, and about what's going on with and around it at any given time, and...

...this is why they don't just grab people off the streets to do this kind of work.

Construction Management is a BASTARD, and no slack ever gets cut, no mercy ever gets shown, and no credit for doing it right ever gets given, and you either learn to swim in that water or you don't, should you ever find yourself having been pushed into it, unexpectedly, and the choice to Get Into the Business is entirely yours, and I'm letting you see all of dirty underside of things here out of the goodness of my heart, so as you might, maybe, thereby be enabled to make a somewhat more-informed decision about things, before you find yourself nostril-deep in this very cold, and very dark, water.

That said, on the other side of the coin, the sensation of getting it right, of making sense of a very difficult technical thing, of finding ways to beat NASA's Rocket Scientists at their own game, is very heady wine indeed, and taking a deep draught of it can be one of the most pleasurable and satisfying things you'll ever experience in your life.

But. You must never forget that as you are enjoying your very-heady wine, you are being supported by a small raft, floating on top of some frighteningly-deep water, and that water is very cold, and very dark, and it will take you if it gets a chance to.

Ok, where were we?

Oh yeah, we were deriving things, and I was warning you about it, because when you derive something off of the Contract Drawings, you are, in essence, buying it. Step one inch away from anything that's in black and white on the drawing, as produced by the engineering, and the contractually-specified entity they work for, and...

...it's yours...

...and if it's wrong and if you failed to submit paper on it in advance, if you had the slightest lingering doubt or question about any of it, well then, that becomes yours too, and depending on the wrongness, the time and money penalties for being wrong can get...

...substantial.

If it was right there on the drawing to begin with, and you're being a good little doo-be, and you're doing what you were told to do, and it turns out to be very expensively fucked-up, then you submit paper on the motherfucker (and yeah, you'd better know how to write, or learn how to write on the double-quick, in a technically-precise and utterly unambiguous way that will withstand high-powered adversarial scrutiny in a court of law), and once the miserable sonofabitches are finally forced into owning their mistake (which may or may not be a quite wild-and-woolly process in and of itself), you get paid for the extra work in the form of a Contract Change Order, and all is well with the world (over on your side of the house, anyway).

But.

Step that one inch away from anything that's spelled out plainly in the contract documents...

...and god help your mortal soul.

So when we're deriving things...

We learn pretty quickly to be very very VERY careful about it, and we double-check and we triple-check, before we...

...commit.

Ok?

And if the OAA bangs into the tower, because we made a mistake in deriving things...

...horrifying amounts of money will suddenly lurch into motion, start swirling around in a mad circle, and then funnel down into a bottomless pit from where it will never return, and...

...are you sure you had your people read... Every. Single. Word. in this thing? All 632 pages of it? Every single bit of it? Because if you missed something in there somewhere...

...Careful there, Lou, this shit's pretty expensive when you get it wrong.

And we have not yet left M-45 The Second behind, and now we move on to 198'-2" top of Canister Guide Rail, and at least this one actually does get spelled out directly on the drawing, and you can see it for yourself on 79K14110 sheet M-70 Section D, which we've previously visited here, and which I'm giving to you again, just to maintain your familiarity with it.

But of course they're not gonna be making any of this stuff easy, and we have to, yet again, derive 0'-6⅜" Clearance between bottom of OAA and top of Guide Rail, because they decided to give us the top elevation for that margin of clearance in Orbiter Coordinate System units, "X_o 559.62," and the bottom elevation for that margin of clearance in the usual feet and inches nomenclature which we're building the tower to, and we must convert one of them into the other, so as they're both the same, and become therefore comprehensible, and we're building the goddamned tower to goddamned feet and inches so ok, so we do the conversion and we derive yet another dimension which permits us to finally understand what the fuck it is that we're looking at here, and...

Careful there, ok? This is an excellent place to get hurt, if you're being insufficiently careful.

And we'll stop right here, and take a look at a marked-up version of Image 031 which is the lead image for Page 30, so as you'll have a better (not good, but at least a little better) chance of properly visualizing this thing.