Reference: Top Bows - 15-cwt truck

[Rolf S. Ask]

Did try a search for bows, but came up with noting...

Anyone having drawings/dimensions on the tarp-bows to go on a C15A??

Have a friend finishing his truck and he is in need of a shelter to sleep under when going to Beltring this summer.

Rolf

[Svenn Ryen]

I need to fabricate top bows for my C15. Does anyone have drawings, templates, pictures or meassurements for these?

Any info apriciated.

Svenn

[cletrac (RIP)]

Yours has the 2C1 body. This info is from Gregg's Military Vehicle Profiles.

[Hanno Spoelstra]

Originally Posted by Svenn Ryen

Does anyone have drawings, templates, pictures or meassurements for these?

Svenn,

See Colin's web page on CMP's and scroll down to the bottom for some details: https://captainstevens.com/military/...tern-vehicles/

PS: I deleted you e-mail address to prevent spamming. People can contact you by clicking on your name and then choose to send you an email or private message (PM)

[Svenn Ryen]

Thanks guys for the info.

But still looking for templates for the bows. Anyone?

Svenn

[George McKenzie]

I will be making a set for my truck and Reg Hodgson has a bow that I am going to use for a copy ,later this winter .I can get you the measurements then

[Svenn Ryen]

Hi guys. I got the oportunity to make templates from the truck on the Norwegian Army Museums C15 (which actually is for sale, see link: http://retrade.no/aitem?aitem_id=120136).

Take a look at the pictures below.

The bow is an original from the norwegian army museum and truck on the link. The flat iron hook is 19 millimeters or 3/4" wide.

But as you can se on the other picture the distance between the edges for the hook on my cargo bed is 24 millimeters. I presume the top bow will move a lot back and forth if I use 3/4" flat iron on my bows.

I believe the cargo bed on the museums C15 is early type 2C1 and mine is late type 2J1.

Was there a change of specifications on these bows at some point?? Or should it just be 3/4" on both types ?? 24 millimeters is also a very strange inch meassure15/16"?? But perhaps it should be 7/8" wide? I believe my tubing should be 1" but on the muesums truck it was 7/8".

Does anyone have a 2J1 cargo bed bows and can meassure the hooks and bows?

I did not meassure the distance on the cargo bed in the museum.

http://www.surfacezero.com/g503/uplo.../IMG_08673.JPG

http://www.surfacezero.com/g503/uplo...918_-_Kopi.JPG

Svenn

[Hanno Spoelstra]

After recent requests, I am going to revive this thread with information at hand. I have merged some threads and moved it from the Softskin to the Restoration subforum.

If you can add to this topic with drawings, dimensions, photos, please do so in this thread.

Thanks in advance!

172612619_1393460904324447_5343422600745447943_n.jpg

172364269_1393460964324441_585153559365784070_n.jpg

[Hanno Spoelstra]

In no particular order, some pictures showing details of the hooks on which the bows hang on the box sides.

This is a set of bows which were copied from original ones.

172049530_1393460710991133_2422461517247455421_n.jpg 171984003_1393460854324452_7539628251361896198_n.jpg 173032763_1393460717657799_389125598285978646_n.jpg

[Hanno Spoelstra]

In no particular order, some pictures showing details of how the cross bars are fitted to the main bows.

This is a set of bows which were copied from original ones.

172706646_1393460934324444_246725055856995307_n.jpg 172695246_1393460850991119_8708885808752698618_n.jpg 172449794_1393460997657771_8816992079186731876_n.jpg

[Bob Carriere]

I will be doing the bows for my 2B1 box and I am working on the assumption that bows for the C15a are all the same regardless of the box designation/size... for greater parts simplicity and interchange........is my assumtion corrct??

I haven ever seen and original set of bows and was happy to discover the "hooks" shown in your pictures.

Would be nice if Jordan B. would chime in with is recent bow expereince even if his are special for the radio truck..

I have concluded that 1 inch diametre pipe was used....BUT what kind...thin wall, thick water pipe or electrical conduit thin wall.

What is the secret to flattening the ends so that the flat piece is off center? I will use a hydraulic press for this purpose and also have a hydraulic pipe bender.

On my cab 11 I intend to use the leather straps and the brass "nipples" of the 2B1...... I realize that I will need to fabricate the leather straps as they were not included on the excellent repros championed by Stewart Loy years ago.

Any record of "bows" having been available that would allow them to be taken apart for easier storage?? .... I do realize that they can be stored forward at the front of the cab when the tarp is not used but they will still be and issue for storing inside my sea container.

I particular like the looks of the C15a with the front and sides rolled up leaving just an "African" looking canvass roof for shade.

Thanks for your help.

Bob C

[Grant Bowker]

From: https://www.atc-mechanical.com/tube-...size-overview/

"Tubing is measured by the OUTSIDE DIAMETER (O.D.), specified in inches (e.g., 1.250) or fraction of an inch (eg. 1-1/4″). Pipe is usually measured by NOMINAL PIPE SIZE (NPS). .... For sizes from 1/8-inch through 12-inch, the NPS corresponds to the nominal inside diameter, but differs somewhat from its actual inside diameter. Early pipe manufacturers made the walls in the smaller sizes much too thick, and in correcting this error in design, they took the excess from the inside to avoid changing the sizes of the companion fittings."

From memory, I think the AEDB record refers to pipe rather than tube for the bows but you should confirm this (feel free to correct me if this isn't true).

I have the impression that someone gave you at least a partial bow (unless it was a replica?). Don't ask me where it might be squirreled away "for safe keeping". If that can be found and measured it could be compared to the tables of tube and pipe size to find the nearest modern equivalent.

No proof of this but I doubt the originals would have been as light as modern EMT (electric conduit) - maybe the standards on that have changed over time too...


Other possibly useful links:
http://www.wermac.org/pipes/pipe_vs_tube.html
https://www.commercemetals.com/tube-...plain-english/
https://www.metalsupermarkets.com/di...pipe-and-tube/
I know Metal Supermarkets aren't the cheapest but their site can be a guide to what is reasonably easy to buy off the shelf in Canada (or USA).

[Hanno Spoelstra]

Originally Posted by Bob Carriere

I will be doing the bows for my 2B1 box and I am working on the assumption that bows for the C15a are all the same regardless of the box designation/size... for greater parts simplicity and interchange........is my assumtion corrct??

I haven ever seen and original set of bows and was happy to discover the "hooks" shown in your pictures.

Would be nice if Jordan B. would chime in with is recent bow expereince even if his are special for the radio truck..

I have concluded that 1 inch diametre pipe was used....BUT what kind...thin wall, thick water pipe or electrical conduit thin wall.

As far as I can tell they are for the 2C bodies onwards, and likely to be the same for the 2B1. But you would have to check with Pete Ashby, he built a 2B1 from scratch.

I will take some detailed measurements in the near future.

[Bob Carriere]

We still have to address the tubing size and how long the legs of the bows are supposed to be to fit an original tailored cab 11/12 tarp????.....

so far I have learned that the early C15a cab11/12 did NOT have the horizontal bars....... pity as it would make the structure much more sturdy.


There seems to be a small bend in the middle of the bows in effect creating a ridge for the water to run from...... what is the angle???

Were the bows made from pipe or tubing??? and what diameter and wall thickness?????

Are the C15a cab11/12 bows ALL in one piece or can they be made with a joining/union sleeve like shown on the 3 ton trucks.

Cheers

Bob C.

[Bob Carriere]

We measured what we believe are original centre ridge pipes.....4 of them that were gifted by David Moore.

Diametre 1 1/16 about 1/8 thick threaded water pipe. Grant is trying to find what out what is currently available for making repro.

Yes Hanno by all accounts (99%) from pictures the 2B1 hasthe floppy bows with no horizontal bars like the cab 13, No happy with floppy bows!!!!

The curious thing about the centre ridge bars is that they are made of 3 pieces joined by thread and a simple union section.

The ex Jon S. cab 13 that is now owned by Gary in Kingston has what I believe is original bows/pipes and original dated 1943 tarp and will get measurements from him soon.

Are the hooks that you showed onMLU from a 2C1 or a early 2B1

Will take some pictures of my box rebuild progress today.

Hoping to do a second coat of POR today if the winds calm down.

Cheers

[Grant Bowker]

The nearest modern equivalent pipe to the ones described by Bob above is 3/4" nominal schedule 40 pipe. The differences in dimension (both OD and wall thickness) are less than 0.010" - close enough that I think it can be called a match.
One interesting observation - the pipes are made in three parts, two shorter at the ends and a longer in the middle, joined by threaded couplers. The ends of the couplers appear to be more rounded than modern equivalents, possibly a modification to make them less hard on the tarp? The construction of the pipe is such that I think it would have always been either fully installed or fully removed. I don't see how it could easily have been set up to allow only two of the three bows on a 15cwt box to be used as would have been possible with the shorter piles pictured above. Also, unlike the pipes shown above that mount to pins, these pipes seem to have been made to be fitted with carriage bolts (remnants of square holes). The ends of the pipes are slightly curved in the flattened section to wrap around the upright and reduce wear on the tarp. The sample pipes are also too long to fit the uprights of a 2B1 box.

However, most of these features (mounting style, single, full length pipe and longer overall length appear consistent with the body for a 8 cwt, which is what David Moore had.

[Hanno Spoelstra]

Bob, Grant,

I'll post my measurements later, first need to transform my scribbling into something presentable.

I also found a refence to top bows for the 2B1 box: there were two types, the second one had the vertical tie bars as on the later 2C1 and upwards bodies.

Not sure what you have there Bob, show us some pictures ;-)

But the 15-cwt top bows were made from a single piece of tube, so no threaded joins with union section. CMPs were not designed to go in a sea can as they had not been invented yet - sorry Bob, but you will have to take off your top bows every time you store the truck. Or discard originality and copy the system on the 3-ton truck where the bows could be set in a high or low position.

More later.

[Chris Suslowicz]

Originally Posted by Grant Bowker

One interesting observation - the pipes are made in three parts, two shorter at the ends and a longer in the middle, joined by threaded couplers. The ends of the couplers appear to be more rounded than modern equivalents, possibly a modification to make them less hard on the tarp?

I think it's just the modern trend for cost-cutting. All the steel pipe unions my father had in the garage/shed (1, 1.5 and 2 inch) all had rounded ends - no sharp edges. These were all pre-1960, I would think. Old conduit 'nipples' were also a 'no sharp edges' rounded end. I think it's only the more recent mass-produced stuff that is parted-off square (and to hell with any cuts the users get from sharp edges - they should wear gloves approach to manufacturing).

Handrail unions are another matter, but they are cast and secured by grub screws (mostly).

Chris.

[Bob Carriere]

Hi Hanno.

I am resigned to removing the bows unless I keep the canvass on full time.

Sea cans are nice and secure but they do have limitations.

My 3 box is definitely 2B1 of which I am making one from the best. We managed to save the best for the rebuild since it has a decent floor and fender wells in place........ yes photos will follow.

My cab 11 is allegedly early production ...Fall 1940 for 4x4....... but the box came from a Cab 12.

It looks like we will be using one piece water pipes schedule 40 (standard) 3/4 ID pipe...... no union. Hoping not to make mistakes in the bending process or will cut.......make and insert....weld and grind and paintover. In fact it maybe easier to do all the bends at the proper radius-ed with my hydraulic bender then fit them together with perfect length.

Now I am not sure if I can used the hooks you showed on a 2B1 in particular the first one behind the cab with the box drop sides and the special corner shaped locking bracket/clamp......

Waiting for the POR to dry right now..... the rotisserie has proven to be a great time and back saver........ how ever when it comes to painting the under side the mounting frame section I am using got in the way ...so we lowered the box on shop horses....removed the u bolts and lifted the rotisserie support as high as we could go then went on with the painting....more like dabbing and slapping the POR coating into every nook and cranny......messy even with rubber gloves. Will reconnect to the rotisserie to finish the top side. Eventually the bottom side will get rubber spray coating then i coat of gloss OD then 2 coats of flat OD. Top side still needs the head board and tailgate fabricated .

Cheers

[david moore]

Bob, Those longitudinal pipes that I gave you - I think the union join is bogus in that the original civvy owner of the F8 here in Kingston (a Mr. Montgomery!) had not realised that the front and rear transverse bows had an offset base to allow the bows to be flush against each respective end. Rather amazingly, he had installed them wrong way round - so needed to shorten the longitudinals by about 6 ins, to match! He cut and rejoined them as they are now. Too short for the correct fitting on the F8 which is why I passed them on! Jonathan now has my old F8 and could check the dimensions of the original existing transverse bows. Tom Lodge and I made the replacement longitudinals from commonly available conduit and they looked fine. The bows on the cab 12 F and C 8's were entirely different from the later C/F15A's - but the pipe may have been the same.

[Hanno Spoelstra]

Originally Posted by Bob Carriere

Are the hooks that you showed onMLU from a 2C1 or a early 2B1

The hooks showed in post #13 are on my truck's 2C1 body.