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ť Forum Name: PT Boats - General
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ť Topic: MARK 6 DEPTH CHARGE
http://www.ptboatforum.com/cgi-bin/MB2/netboardr.cgi?cid=101&fid=102&tid=1725

How long was the Mark 6 depth charge used by the Navy? I want to machine full size bronze end pieces for display on PT 658. Jerry Gilmartin sent me some assembly drawings for the Mark 6. These drawings do not have any dimensions on them. I doubt BuOrd would send me a set of drawings for a depth charge. Any parts or drawings out there? I can scale the drawings and come close, but any parts or prints would be helpful. Any depth charges on display at Battleship Cove?

Posted By: RUSSELL WHIPPLE | Posted on: Mar 23, 2010 - 2:51am
Total Posts: 13 | Joined: Dec 16, 2007 - 9:38am

If I remember correctly, the Mod.6 Depth charges were roughly 28 inches long with an 18 inch diameter. I think I am pretty close with those numbers.............

Posted By: Frank J Andruss Sr | Posted on: Mar 23, 2010 - 3:29am
Total Posts: 3497 | Joined: Oct 9, 2006 - 6:09am

Good luck Russell, mighty nice of you.

The HNSA site has a depth charge manual online:
[url]http://www.hnsa.org/doc/depthcharge6/index.htm[/url]
Pretty close Frank, according to the manual:
[blue]6. All of these charges measure 27.625 inches long.
(a) Mark 6 and Mark 6 Mod. 1 each weigh 420 pounds complete-and are 17.625 inches in diameter.[/blue]

I hope the images from the manual are accurate enough for this to be useful:

[image]http://www.pt103.com/images/Depth_Charge_MK_6_Drawing_Gridded.jpg[/image]

Posted By: Jeff D | Posted on: Mar 23, 2010 - 6:51am
Total Posts: 2200 | Joined: Dec 21, 2006 - 1:30am

When did the Navy stop using the Mark 6 depth charge? I would guess that depth charges were not used much after WW2.

Posted By: RUSSELL WHIPPLE | Posted on: Mar 23, 2010 - 9:13am
Total Posts: 13 | Joined: Dec 16, 2007 - 9:38am

Not sure when they stopped using them, as advances in underwater depth charges were improved. The Navy soon realized that the chances of hitting a sub with one depth charge were remote, so they came up with the Hedge-Hog system. Depth Charges to my knowledge are still used in today's Navy..........

Posted By: Frank J Andruss Sr | Posted on: Mar 23, 2010 - 11:51am
Total Posts: 3497 | Joined: Oct 9, 2006 - 6:09am

Not sure how far you're going with this, but here is the Type C rack used on the boats:

[IMaGe]http://i73.photobucket.com/albums/i204/alross2/dc1.jpg[/IMaGe]

Al Ross

Posted By: alross2 | Posted on: Mar 23, 2010 - 1:22pm
Total Posts: 993 | Joined: Oct 30, 2006 - 8:19pm

Russell,

The use of the MK 6 came to an end towards the end of World War II. The navy moved towards the tear drop shaped charges as submarine underwater speeds increased, specifically the type XX German U-boat. The MK6 trash can shape created a slow sink rate, by the time the charge got to deeper depths, about 300 feet, a fast submarine had left the drop zone. I think the USNI book on Destroyer Weapons covers the history of these types of charges.

Bill

Bill Smallshaw

Posted By: smallwi | Posted on: Mar 23, 2010 - 3:32pm
Total Posts: 134 | Joined: Jun 21, 2007 - 3:02pm

What a super web site! Thanks to everyone for the great help. I want to machine from bronze all the pieces that fit inside the 6 1/2" diameter flange that bolts to the can using 8 bolts. Want to make this thing look real.
Jeff, how did you get a grid on this drawing?
Thanks, Russell Whipple

Posted By: RUSSELL WHIPPLE | Posted on: Mar 23, 2010 - 5:44pm
Total Posts: 13 | Joined: Dec 16, 2007 - 9:38am

It was done in a 3D program Russell. Although like I mentioned, I'm not sure how accurate the drawings are...

If you have higher resolution images I can grid them up for you. How sure are you of the 6.5" diameter of the flange? I see the gridded drawing seems to match.

Posted By: Jeff D | Posted on: Mar 24, 2010 - 1:45am
Total Posts: 2200 | Joined: Dec 21, 2006 - 1:30am

Hi Jeff,
The 6 1/2" dia is a scaled (guess) dimension.
The only dimentioned dwg I have found is on page 68 of hnsa.org. article that you made available.This is a dwg of the dial plate. The dial plate outside diameter is 3.495 +0/-.005. Thickness is .3125.
Can you use these real dimensions?
Thanks, Russ

Posted By: RUSSELL WHIPPLE | Posted on: Mar 24, 2010 - 12:14pm
Total Posts: 13 | Joined: Dec 16, 2007 - 9:38am

Thanks Russell, the drawing looks like it's pretty close.

Posted By: Jeff D | Posted on: Mar 24, 2010 - 5:23pm
Total Posts: 2200 | Joined: Dec 21, 2006 - 1:30am