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Lunar Module Porch and Ladder

Kit vs. Reality

The photo below show the kit part for the porch.  According to David Weeks drawing sets, the porch is too long.  The railing is shown next to David's drawing.  Note the pencil marks on the railing, which is where I cut it.  As it turns out, I have the railing reversed (left right) from the way it should be.

original porch

original railing

Note that the porch has a bend in
it, and the short portion needs to be closest to the hatch.  In building my model, I cut off three ridges worth of the lower section.  I probably should have cut two from the bottom and one from the top.  I added some plastic strip along each side since the "treads" did not extend to the edges of the porch.  Of course, the original mounting holes for the railings are not accurate, and need to be removed.  If you install the porch per the kit instructions, you've installed it backwards.  They have small nubs on the bottom that are supposed to mate with holes in the descent stage.  But that puts the long section towards the hatch, which is wrong. 

split porch

Problems with Museum Exhibits

What also confused and bugs me is the inconsistancy in the way the side railing are installed on several museum displays.  The railings have a long leg with a gentle bend that should be closest to the hatch.  The other leg of the railing has a larger radius bend but bends at an overall sharper angle, and goes towards the ladder.  The photos and drawing below illustrate the actual configuration.

The first photo is from the Apollo 15 mission.

Apollo 15

This next photo is of LM-6 at KSC courtesy of Mike Robel.


This is an excerpt of what seems to be an accurate drawing.  Note the sharp, smaller radius bend closest to the hatch, while the bend at the right is gentler (larger radius).


Now look at these photos below.  The first was provided by Karl Dodenhoff, and was taken at KSC (?).  It appears to me that the railings are installed backwards.


Also note how the top rung of the ladder is in the conical portion of the leg, while in reality the first rung is a little lower.  The kit repeats this error, with the first rung in the conical section, which is probably an earlier configuration.  I did not catch this in my model.

In this photo of the LM at the Kansas Cosmosphere museum, provided by Mike Idacavage, there is one railing installed okay (towards the top of the photo), while the other is backwards.  It also has the top rung of the ladder in the cone.


The Ladder

Let's look at the ladder a little closer.  The kit part has 10 rungs with the top rung buried in the conical section of the leg.  The real 
ladder had 9 rungs with the top one below the conical section.  The photo below is the LM at the Alabama Space and Rocket Center in Huntsville.  It appears to have an accurate ladder (although the blanket colors appear to be for an early mission - there was more orange kapton in later missions).  I don't have a good photo of the Huntsville porch, but it appears to be a poor reproduction and not even close to a flight or engineering version.


The photo below is from Apollo 11, and note how this matches the Huntsville display but not the kit.


You cannot cut off the top rung on the kit part because it bends at the correct place (at the third rung).  I did not want to cut off the bottom rung because it has the nice attachment piece.  Unfortunately, that lowest attachment point should be at the rung second from the bottom (see photo above).  Short of rebuilding it from scratch (it would be a pain to make it square and uniformly spaced...), I just cut it in the middle, with offset cuts to maximize strength and straighness. 


This is the final result of the model.  It's not perfect but it's reasonably close.


As has been my philosophy with this model, "done" is better than "perfect."

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This page created Jan. 1, 2007