modeling for success

[little seacoast]

     I have started a model of a generic barbette carriage in anticipation of having to build a much larger one soon.  This one will hold my Sawyer Rifle in 1" bore and is simply a test bed, a little rough.  I will post a few pics as I go along, constructive criticism always welcomed, I'd rather goof up and fix it in this small scale.
 

[little seacoast]

pictures, finally

[seacoastartillery]

     Looks like you have a very good start.  The proportions looks good and the brace to base bolts have good positions.  On the big one to follow this one, you may want to consider placing the base to base, transom bolts immediately behind the transoms instead of thru them.  It's authentic and easier!  Also the addition of the mechanical wood locking notch about half way on the bottom end of the brace where it contacts the rear top of the base timbers is authentic and looks great.  Your proportions look good, but it's hard to tell if the brace is the same height as the base timber.  Typically the heights run 14", 12", 10" (support, base and brace).  We had to go bigger with the Brooke Upper Carriage, because the originals were 18", 16" and 14" because of the 21,000 pound tube instead of a typical 10,000.

     Is it O.K. to ask why you have to go bigger with the next one?  Is it a Great Turkish Bombard of Constantinople? 

Tracy and Mike

[little seacoast]

Thanks for the feedback, that one is strictly eyeball on measurements and proportions, glad to have some specifics to work with. I agree that mechanically notching the supports in will add a great deal of strength, that's a definate change list item.  Re the bolts are you referring to the 45 degree bolts that enter behind the trunnion and exit the front or others?
I put those that way due to an old pic I found that looked like that, It was a bear to get them to just miss the cross  frame bolt. That would also be a welcome change list item.  Now for the front pivoting carriage or is it called a slide or what.

[seacoastartillery]

     OK, I just read your other post on the Florida gun.  I think I know why you will be building another Barbette Carriage now.  SBR!  I think you did well.  Their stuff is the best cast iron cannons that we have seen. I own three, myself. 

     The bolts I'm talking about are those that are horizontal and go from base piece to base piece through the transoms.  All I'm saying here is that you can save yourself a lot of difficult long hole drilling if you place those transom holding bolts immediately behind each transom rather than thru it.  It's authentic too.

 Now for the front pivoting carriage or is it called a slide or what.   

     We call that a Chassis.  Almost all of the seacoast guns were fired over the parapet in a Barbette configuration.  These large gun tubes were placed on an Upper Carriage (like you built) which gave the tube elevation and depression capability and was supported by a two or three rail Chassis upon which the Upper Carriage was fired.  During recoil the gun slid back on long, narrow iron plates that were screwed to the timber rails.  Then gun was then re-loaded, the eccentrics were engaged and the carriage and tube run forward into "Battery" position, ready for firing only after the eccentrics were disengaged.  The center pintle type Chassis had 2 sets of 2 wheels and could do a 360 degree turnaround on a circular, Traverse track, while the Chassis of the Front Pintle type rested on a Pintle Plate in the front and 2 traverse wheels in the backand was limited to about 120 degrees of traverse.  The Platform which supported the Gun, the Traverse track, Pintle Pin, Artillerymen and their equipment was made of lumber and heavy timbers or cut stones, bricks and earth.

     Remember too that the bolts for the cross pieces (transoms) on the Chassis can also go immediately behind the transoms and be authentic.  Bravo!  You have used the right size washers and nuts.  They were big on those old guns to avoid "cratering" the wood.

Can't wait to see the other in process pics.  Take plenty!  Please know that none of our comments are criticisms.  You are doing a super job.  Keep on truckin!

Tracy

[Zulu]

Thanks for the feedback, that one is strictly eyeball on measurements and proportions, glad to have some specifics to work with. I agree that mechanically notching the supports in will add a great deal of strength, that's a definate change list item.  Re the bolts are you referring to the 45 degree bolts that enter behind the trunnion and exit the front or others?
I put those that way due to an old pic I found that looked like that, It was a bear to get them to just miss the cross  frame bolt. That would also be a welcome change list item.  Now for the front pivoting carriage or is it called a slide or what.

LS,
My attempt at a Barbette carriage had the 45 degree bolt running between the front transom bolts.
That was a trick!
Zulu
 

 
 

[little seacoast]

Zulu, I looked at the pictures you posted before and decided that that just wasn't gonna happen for me, that's precision drilling!  M&T thanks for the very useful suggestions and yes the cross brace bolts certainly will be done the way you have suggested, that is a real labor saver.  As always you two seem to have a great grip on the "how to" and research.  I'll take plenty of pics, there are quite a few made already, just not posted as I wasn't sure if there would be any interest. Thanks, Pete