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Starting with at least the 77 footers in 1941, and possibly even earlier with the 70 footers, Elco used cradles fabricated from steel I-beams to trundle the boats around the yard, hoist them into the water, and for trans-oceanic shipping on the decks of tankers. With modifications for hull shape, they were also used for the 80 footers. I've got no idea how many were made, but I assume they were some of the earliest "returnable packaging", probably being cycled back to Elco on the decks of the returning tankers.
I've found several photos in books (see bibliography) that show Elcos on these unusual A-frame cradles. These pictures are somewhat fuzzy; perhaps if the originals can be found and examined (see PT Boats Inc), then more detail could be discerned. I've taken the liberty of reproducing some details here.
 (1)
PT-109 in it's most famous role- these pictures were taken for an instruction book on how to stow PT's on tanker decks. Hull supports of a cradle on the pier are just visible.
Anyone know if this how-to manual still exists?
Aft view of 109, fore "wing"of cradle just visible. Click on picture for close-up of stacked cradles dockside. (1)
Bow view of 109, showing hull supports and guide post. Click on image for a close-up. (1)
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I also have an Elco factory drawing which shows how to rig the sling for hoisting a 77 footer on a cradle; this drawing gives the outline of the cradle, but not all the details.
 (4)
With these bits of info and my own deductions, I've generated drawings of the cradle. I've made some adjustments to the beam sizes to allow use of Plastruct ABS beams for a 1/20th model; the sizes are scaled off the Elco drawing anyway, so some guessing is involved.
Clicking on the images below will take you to larger GIF's…due to the fine lines, they might not display well on your screen, but you can save them to disk (right click with your mouse)… then you can print them out on 8-1/2x11 paper.
I have the CAD file, but haven't created dimensioned drawings yet… when they're ready, I'll post those too.
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A few notes on the structure:
* This is a massive structure, the main beams are 18x9 inch I-beams.
* No cross bracing is used for the vertical hull supports... unusual, but the riveted beam construction must have been enough to keep the structure from "lozenging" and collapsing.
* The hull supports are shaped wood beams laying on top of steel I-beams.
* These beams MAY have been pivoted at the center, to allow for knock-down and possibly adjustment between the 77 and 80 foot hull shapes. I can't see this clearly, but the vertical supports have something that looks like pins or through-bolts at the upper end to fix the hull support beams... that would be consistent with knock-down capability.
* The structure sits on wheel sets... I've got little detail on these, but the Elco drawing indicates "tillers" at each end, which imply that the wheels sets could swivel. I don't show the tillers.
* Beam joinery is by riveted angle plates; I don't show these plates or gussets in the drawing.
* Lift eyes are flat plates attached to the tips of the "wings", four in all.
* Guide boards are attached to help maneuver boats onto the structure in the water... two forward, one aft on the port side.
* From the light color in the photos, I assume the paint was light naval gray. I can't see any markings, but I can imagine a stenciled "Return to ELCO, Bayonne, NJ"!
* I'm still building both my cradle and my 77' foot model, so I can't comment on the strength of the model cradle... but I suspect that in plastic, it won't be very stiff, and might need to be attached to a board for safe transport and display of your model. |
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If you have any more info on these cradles, or better pictures or drawings, or if you build one for your own model, I'd like to hear from you.
The only drawings I've researched are for the 77 foot boats... I have a roll of microfilm from the National Archives, which are of incredibly poor quality- see scans below. Possibly a visit to the Archives or to PT Boats would turn up the originals, maybe even the actual cradle detail drawings... a search for 80' drawings might also uncover more info.
The Johnson book also has a couple pictures of the Higgins cradle, which seems to be of lighter construction with more diagonal bracing. I haven't looked for any drawings of that one. |
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PT-47 on sling, perhaps in Panama?(6)
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77 footer on sling at Melville (1)
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80 footer on sling, I think in Europe. I found this on someone's web site, I forget who… if you know, please let me know for credit's sake… (3)
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80 footer backing off cradle in the water at the Elco yard (5)
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More PT's on a tanker, cradle just visible.(2)
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New hull being dropped onto cradle at Elco (1)
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77 footers of RON 3 on the way to the Philippines, cradles just visible. These are some of the last photos of Bulkeley's "expendables". (2) |
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PT being hoisted onto tender, using a homebrew cradle. I guess the A-frames didn't stay in the field. (2)
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e-mail me! Pat Matthews patmat2350@sbcglobal.net |
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References
- United States PT Boats of WW2,
F.D.Johnson, Blandford Press Ltd, ISBN 071371025X
- PT Boats at war: WW2 to Vietnam,
N.Polmar & S.L.Morison, MBI Publishing, ISBN 0760304998
- Unidentified web site
- National Archives, RG19, Roll #310, Elco 77 foot Motor Torpedo Boat PT-20 Class
- Elco PT- World's fastest Combat Vessel,
Elco Naval Division (magazine format, reprints of various PT articles)
- forwarded by Gene Kirkland
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