Warbird Information Exchange

OK - here is one for you - in the photo the trailer is the subject!

It is stenciled "Utility" on the front left side and just ahead of the rear left tire there looks to be a larger amount of stenciling as well. I am guessing this trailer started life as a standard issue cargo/ammo transport trailer? Any help or thoughts would be greatly appreciated as to make / model etc. . .

[url=https://flic.kr/p/2mSMW4T][/url

Tom P

Tom: You might drop the Atomic Heritage Foundation a note and see if they have anything. I have a sneaking suspicion that it was fabricated on Tinian from something already there.

I agree, the thing that throws me is the "data plate" stencil forward of the rear tires on the frame (why do that on a custom one off trailer?) and the bends in the I-beam frame - that is pretty stout stuff to get that nice of a bend in the field and leads me to think that this is a modified bomb trailer of some kind - BUT WHAT?! lol

Thanks and I will reach out to them - my guess is its pretty rare since the NMUASF has thier "fatman" on a cart unlike this one. Maybe its a USN utility cart??

Tom

More trailer pics here, https://www.alternatewars.com/Bomb_Load ... _Guide.htm

_________________
45-47=-2

Mike - very interesting, thanks for the link. I'm curious about the lineup of weapons in the forefront of the first image. I'm away from home and my library but they look to have some sort of air-breathing engine in the nose, perhaps an Argus-style pulse jet? They differ from the JB-2 Loon engines but have a similar look. Don't think I've ever seen a photo of one before. Anybody have more info on them? Thanks, and a Merry Christmas to all.

Randy

Randy: Those are gun tubes for Little Boy's. The fission material sections were crushed together in the large end of the tube.

Thank you very much. I don't think I ever saw them from this angle with the tailfins fitted. All the best.

Randy

It almost looks like a transport mount for an AA gun. It doesn't jive with any thing I come up with on a quick search, but it was just that, quick

_________________
Lest Hero-worship raise it's head and cloud our vision, remember that World War II was fought and won by the same sort of twenty-something punks we wouldn't let our daughters date.

Correction, those shapes in the first picture of the link Mike shared are not Little Boy gun tubes, they are the full test drop shapes of the "Thin Man" device. Early in the program for the plutonium device, it was thought that a long barrel type device would be used to bring masses of plutonium together into a critical mass (like was done for the uranium Little Boy). By Mid 1994 the design for the plutonium device had settled upon the the lens type device known as fat man, where lenses of conventional explosives compressed the plutonium sphere into a critical mass.

Numerous test drops of all three type shapes (Thin Man, Little Boy and Fat Man) were conducted the the ranges near Wendover and the Salton Sea, primarily from Wendover. The photo was taken at Wendover in 1944. Maybe Wendover Tom can ID where the photo was taken? Looks like quite a berm behind the shapes.

Randy, I imagine the front of the Thin Man shapes had a detachable plate for the loading of weights or marking charges, and that is what you are seeing.

https://en.wikipedia.org/wiki/Thin_Man_(nuclear_bomb)

Yes that is correct -those are "Thin man" prototypes.
The photo is a bit of a challenge though! It is labeled as being Wendover, and if you have a high res copy you can tell they are actually sitting in a large pit or something with huge revetments - something that large we have not ever seen evidence of at Wendover. Not that it isn't here its just if there was something like that it has been very well concealed. One thought is that since the thin man design was eliminated very early on this photo MIGHT actually be at Inyokern - but I have nothing to offer to back that up.

Tom P.

Seems to me with all the planning that went into the atomic program that no one would think of the need for a bomb trailer ahead of time and thought "Let's have the 509th come up with (or jury rig) something".

_________________
Remember the vets, the wonderful planes they flew and their sacrifices for a future many of them did not live to see.
Note political free signature.
I figure if you wanted my opinion on items unrelated to this forum, you'd ask for it.

You are correct. This is one of a series of photographs taken at Tinian that are in the National Archives. The good news is that a number of the others show the trailer from different angles:

(Source: National Archives)

(Source: National Archives)

(Source: National Archives)

(Source: National Archives)

(Source: National Archives)

(Source: National Archives)

If you zoom in, there's a stencil visible forward of the rear wheel on the frame of the trailer on image 77-BT-175. It's difficult to make out, but it appears to read "ASSEM. NUM.". There's also a data plate just barely visible above the near tire in image 77-BT-174. Taken together, this pretty definitively establishes that this was not a scratch built piece of equipment.

Not sure if its the same trailer, but there's also a photograph of the one used to load Little Boy that shows the structure a bit better:

(Source: National Archives)

I think your best bet for identifying the trailer would be to look through old stock/supply catalogs. I checked two I know of on AirCorps Library (1, 2) and another on HathiTrust.


The National Museum of Nuclear Science & History has a more modern MHU-7/M underneath their B-52. Their indoor Fat Man mockup is just sitting on a stand, but they have a scale model that depicts the trailer.

_________________
Tri-State Warbird Museum Collections Manager & Museum Attendant

Warbird Philosophy Webmaster

Possibly an engine stand for those big 3350's, looks similar to the ones that were used at NAS Agana Guam by the NAVY engine overhaul shops.

Behind the right front wheel is a white rectangle with the word UTILITY in it.

_________________
45-47=-2

Thank you everyone! I was able to track it down in part due to your input!

It was a specifically built trailer for the Manhattan project - although the manufacturer probably had no clue what it was made for at the time.

In a atomic bomb loading manual from the post war era - 1946 anyway - the manual calls for and provides drawings for a bomb trailer made by, wait for it. . . . Utility Trailer manufacturing! The reason I say they probably had no idea what the trailer was for at the time is that on the drawing the trailer is called a "Cal-tech lowboy trailer" My guess is that the final arrangement of the bomb cradle was done by the 603rd Air Engineering Squadron or the 1st Ordnance Squadron on Tinian.

Anyway, now I just need to convince someone to build one for the museum.

Thanks again for your help!

Tom P.