Apollo 11 Lunar Surface Journal

Apollo 11 LRRR Clevis-and-Tang Fasteners

Commentary Copyright © 2011 by Eric M. Jones.
All rights reserved.
Mike Blaney, Ken Glover, and Vlad Pustynski
contributed to this discussion
Last revised 21 April 2011.


Apollo 11 LRRR fitting in 5952

Detail from 5952 showing a fitting that secured the LRRR in the SEQ Bay.
The relevant section of the final Apollo 11 Lunar Surface Operations Plan
indicates that, probably during training, the fitting came to be known as
the "hockey stick". At each end is a clevis fastener. The end on the right
was fitted to the base of the LRRR package and, hence, was below the one
on the left, which was attached to the deployment boom in the SEQ Bay. Near
the bottom clevis (right) is a red clevis pin attached to a cable which, in turn
is attached to the top clevis (left). (Click on the image for a larger version.)


Clevis-and-Tang Fastener after PSF

A clevis fastener is a three-piece system consisting of a clevis, clevis pin, and tang.
The clevis is a U-shaped piece that has holes at the end of the prongs to accept
the clevis pin. The tang is the piece that fits between the clevis with a hole that
allows the pin to penetrate the tang and tie the tang and clevis together.  In the
case of the Apollo 11 LRRR fitting, the pin is designed for easy removal during
offloading. Drawing of a nautical example modified from original donated
to the Wikimedia Foundation
by Pearson Scott Foresman.

Apollo 11 LRRR fitting in 5928

Detail from AS11-40-5928 showing the LRRR fitting in it's pre-offload configuration in the SEQ Bay.
Buzz is preparing to offload the seismometer package from the left side of the bay.

Detail from 69-H-675


Detail from training photo 69-H-675 showing Buzz offloading the LRRR.
Once he grabs the LRRR, he will remove the upper clevis pin.
(Click on the image for a larger version.)

Upper Clvis in S69-32250

Detail from training photo S69-32250.  Buzz is carrying the
EASEP package away from the LM simulator, with the LRRR
fitting still attached by the lower clevis fastener.
(Click on the image for a larger version)

Upper Clevis in enhanced detail from 5942

Detail from AS11-40-5942 shows the thin ring used to pull
the upper pin and the in-place pull ring for the lower pin.
Placement of the lower pull ring suggests that Neil will
pull that pin and remove the LRRR fitting before
tipping the LRRR onto its base.
(Click on the image for a larger version.)

LRRR in 5945 detail after Buzz puts it on the surface

Detail from AS11-40-5945.  Buzz has just put the LRRR
on the surface.  Before deploying the LRRR, Neil will put the
ALSCC he's been carrying on the flat rock at the lower left and then turn
the LRRR so the base in facing away from the Sun.  (See AS11-40-5952.)
Details of the deployment procedures can be found in an extract from
The Apollo 11 Lunar Surface Ops Plan.
(Click on the image for a larger version.)

Detail from S69-31200 with lower clevis removed

Detail from training photo S69-31200 showing the lower clevis
after removal, along with a cover that protected the reflectors.
(Click on the image for a larger version.)

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