Bob,

Just a quick comparison. I think this is how it matches up. Still the metal seems light to me, but the shapes all match. I think the sheet metal is the axle band--if you look, you can see it is rounded somewhat that would match the rounding of the axle. As you can see, it goes on the bottom of the axle.

I did these really quick, so they are not website quality, but they will get you the idea.

Paul

A larger photo by Russ Gray of Reno.

More information

Ed. Note: These carriage plans are for the M1828 French Mountain Howitzer. The US M1835 was a copy of the French carriage, which went through a number of modifications before being standardized in 1848 following the Mexican War. There are other differences, because the US copy of the French Tube, as cast by Cyrus Alger in Boston, had the trunnions placed on axis with the bore, rather than under axis on the French tube.

May, 2011. Here is a recently obtained photo of the as-recovered assembly which shows details of the trunneon plate; specifically, the forward area with the two rows of perforations.

Paul Rosewitz comments:
Yes Bob, you are correct. The Trunnion strap is depicted in the plan before it is bent. there was a jig they used to bend the strap into place hot and then fitted it to the pre-cut wood stock. The 1841 Ordnance manual that described this piece states: 2 trunion plates, fastened each by 3 bolts and 6 nails; 2 key bolts. 2 chin bolts, 2 rounded head bolts.

The later carriage (from 2nd edition Ord. manual ,1850) actually only used three nails per plate, the two at the end of the stap and one in the center of the stock this carries over to the 3rd ed ord manual. These were positioned differently and sometimes they were all on the front in a triangle or one in the center and two in the lower bend.] But for our discussion the French model as depicted in the plan has eight per strap. The manual calls for six. I can't see the recovery picture well enough to see how many holes are actually present on the strap other than the two on the end that would have been covered by the end of the axle stap.

Below is Bob's digital measurement of the tire diameters from Herb's photograph taken at the Ranger Station in Bridgeport.
Herb measured the glassed opening in the display case at 36.5" by 36.5". Using Adobe Photoshop^®, the corners of that image of the opening were dragged onto a grid to remove vertical and horizontal camera distortion. From a number of index points placed on the edge of foremost tire rim, a number of digital measurements were made through the center of a circular overlay. The tires are not quite round--a mean was taken.