PT Boat Forum


Moderated by: Dick, Jeff D

The PT Boat Forum ª PT Boats of WWII ª  PT Boats - General

Prev Page | Next Page | Page: 5 of 6

Back to Topic Index Page 76 | Replies: 55 | Pages: 1 2 3 4 [5] 6

 Author  Topic: Loading Torrpedos in Tubs.
Jeff D

Moderator
  

    
Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Jeff D   Send Email To Jeff D Posted on: Apr 29, 2013 - 12:33pm
Here's some tube lengths from ordnance drawings Al Ross supplied, and torpedo lengths from the site Al posted:

Tube length from muzzle to end of door flange: 242 7/8".
Door goes in the tube 2 11/16".
Which leaves about 240" open length.

Torpedo lengths:
Mark XIV torpedo: 240"
Mark XIV torpedo with elongated warhead: 246"
Mark VIII-3D torpedo: 250.88"

I don't know how far back the torpedoes sat when secured.



Total Posts: 1776 | Joined: Dec 21, 2006 - 1:30am | IP Logged

Jeff D

Moderator
  

    
Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Jeff D   Send Email To Jeff D Posted on: Apr 29, 2013 - 1:41pm
I asked Jack some questions, here's his response (after my questions):

Was the ring on the front only on exercise heads, for towing it back after use? Most photos of boats in action seem to lack the rings. Questions were asked if the ring was screwed into a war head for loading then replaced with a smooth cover.

Did any torpedoes stick out past the end of the tube? I see on this page that lengths varied: http://www.ibiblio.org/hyperwar/USN/ref/PT-Manual/MTBM-2.html#C6. An image from a History Channel show seems to show a torpedo sticking WAY out, but it may be already starting to launch:



Double answer: No idea about the shark face sticking out but the exploder impeller, the little water wheel thingie that arms the warhead, would have been exposed while trained outboard and allowed to turn without some sort of lock on it. Such lock would have to be fastened to the boat -- a lanyard or some such -- to strip away upon launch. Never can recall seeing any shark faces on fish. Maybe the memory banks got erased, though. Wouldn't the gaudy white paint show up easily in darkness???? Maybe Melville or Newport Torpedo Station?

Nose ring on exercise head; used to attach line to hoist or retrieve the torpedo at the end of its run to return to the shop for overhaul. A crane hauled it out of the water where it was floating vertically nose up. Torpedoes ran about $10,000 each if those memory banks are functioning. That was a fortune in those World War One days when they were built, so they had to be recovered and used over. My log says my newest Mk 8 was made in 1919! WW1 surplus???

A war head didn't need a nose ring for loading into the tube. That was done horizontally. Imagine the screws holding the war head to the air flask while vertical giving away with the resultant damage. A torpedo cart always carried, stored and loaded a Mk 8 horizontally. They were BIG!

My brain hurts! It ain't worked that hard in decades.

Remember, all, I had another 42 years of service memories to sort through to go back to 1943. In fact, I can't tell you where or when we took off the tubes and exchanged them for racks. Rendova, Tulagi?? Memory wiped out! The Base Force Bastards did that kind of grunt work, anyway, while we crewmembers helped somewhat by supervising. Otherwise known as watching after offering to help. Also, I was a somewhat traumatically overwhelmed 18-year-old at the time of that occurrence and we only have one torpedoman aboard. Strikers were assigned later on as we added guns.

Pretty sure we got the self-sealing gas tanks to replace the aluminum ones at Treasury. I would not place more than a lunch bet on that, however! Or that might have been where the base force put the armor plate on the sides to protect the tanks. Don't remember how the armor was attached, either. Motor Mac stuff. No' my yob, man!

Jack


I think that on the Mark 8 torpedoes, the ring was only on the excercise head.

The torpedo shown above with the shark face was probably a Mark 14.

I noticed that Devil Boats shows what looks like the triangle retainer loosened:






Total Posts: 1776 | Joined: Dec 21, 2006 - 1:30am | IP Logged

Drew Cook

TOP BOSS
  

    
Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Drew Cook  Posted on: Apr 29, 2013 - 1:55pm
I'd have to disagree with Bob on the "no live warheads" as far as the Italeri PT 109 kit parts.

The torpedo nose parts with the molded-in triangular "bra" plates and cables are meant to represent live warheads -- just like in the photo of the 149's torpedoman cranking the tube out into firing position.

Those aren't "caps" or "covers" -- in the 149 photo or the Italeri parts.




Total Posts: 1241 | Joined: Oct 19, 2006 - 10:44am | IP Logged

David Waples

TOP BOSS
  

    
Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of David Waples  Posted on: Apr 29, 2013 - 8:24pm
Jeff, you nailed it. That's the image I referred to earlier. One has holes. One does not, or appears not to have them. It has a bonze like tone to it at least in these photos. Jerry Beasley is going to reach out to the Navy Torpedo Museum and find out what it is that we're dealing with in this photo. One step closer to solving the mystery.

If the ring would be used in the loading process I think it would be used for unloading... I think. One of the drawings we have for the torpedo tubes is of the winch system that is purpose built to attached to the breach of the torpedo tube. Drawings below. We see in the photo of the torpedo being loaded onto a series of rollers on the deck of a 77' Elco. I can imagine that once the torpedo is rested on those rollers it can be winched into the tube, or gravity may assist because of the downward slope of the deck. Not sure how you would do the rear tubes though. Maybe somebody has some info about that?







David Waples

Total Posts: 1583 | Joined: Jan 2, 2007 - 9:55pm | IP Logged

ducati650

TOP BOSS
  

    
Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of ducati650   Send Email To ducati650 Posted on: Apr 30, 2013 - 5:55am
If I might offer my speculation about this.

I think the bronze circular area shown on the warhead indicates that the rings are removable and that these particular warheads had been painted with the rings in place and then, at some point, the rings were removed.

I suspect the rings interfere with the small triangular retainer and possibly with the larger, full-sized cover so the rings were removed.

It would seem that the rings were not needed to load the torpedos into the tubes but, I suggest, they were re-attached when it came time to remove a torpedo from a tube.

I think the kit's piece with the triangular cover models a retainer on a live warhead and the other piece is a full size cover.

Just my $0.02-worth.


Total Posts: 450 | Joined: Feb 19, 2007 - 10:01am | IP Logged

Rock1947a

New Member
  

    
Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Rock1947a  Posted on: Apr 30, 2013 - 11:00am
Hi everyone.

Pages 11 and 12 of the U.S. Navy February 1943 Motor Torpedo Boat Manual
describes 1/4-inch steel-wire bridles used to secure over the torpedo war head on Mark 18-1 tubes. The rest of that section is very interesting too.

http://www.ibiblio.org/hyperwar/USN/ref/PT-Manual/MTBM-1.html

Torpedo tubes.--Due to the necessity for keeping torpedoes ready for firing at a moment's notice, tube covers are no longer kept on the tubes. Therefore, in order to insure against stop pins shearing and a torpedo unexpectedly slipping out, all Mark 18-1 tubes should be equipped with 1/4-inch steel-wire bridles to secure over the war head. This bridle has a tripping latch which can be tripped in a second once action is expected.

To replace the watertight features of a tube cover, a heavy axle grease packed liberally in the seam between the tube and the warhead will prove very satisfactory.

Tubes should be dove once a month and slushed. Kerosene or paint thinner can be used to clean tubes. A good slush is a mixture of heavy grease and hot-running torpedo oil. Care must be taken to prevent grit, etc., from getting into the tube as a small amount of grit will cause a long deep scratch oh the air flask.

Torpedoes.--Since torpedoes are the most important piece of equipment on a boat, no effort should be spared in caring for them.

New squadrons getting torpedoes should inspect them immediately for defects. One defect was discovered in the starting lever of a torpedo which was too long. The torpedo was loaded in the tube without difficulty but a small amount of friction tripped the lever and started a hot run.

War heads.--War heads hit by .50 caliber bullets are not apt to explode on impact; however, they will probably start burning and explode shortly; therefore, war heads ignited in this way should be disposed of by firing the torpedo or otherwise jettisoning it.

I think the bridle (torpedo retention bracket?) is depicted in Italeri's PT 109 kit as the alternative to the domed tube cover. I'm sure I've seen an illustration or photo of this bridle with the triangular plate next to a tube cover somewhere in my reference books or on the internet, but for the life of me, I can't find it now.

I hope you find this information useful. I intend to use the Italeri bridle over the warheads on my kit.
Pete




Total Posts: 24 | Joined: Mar 1, 2007 - 10:56am | IP Logged

Jeff D

Moderator
  

    
Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Jeff D   Send Email To Jeff D Posted on: Apr 30, 2013 - 12:10pm
Great catch Pete, thank you! It also answers a question I had about how water was kept out without a cover.



Total Posts: 1776 | Joined: Dec 21, 2006 - 1:30am | IP Logged

Wayne Traxel

MASTER
  

    
Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Wayne Traxel   Send Email To Wayne Traxel Posted on: Apr 30, 2013 - 12:17pm


Found this shot of PT-157's bridle fitted to Starboard Torpedo Tube. Same picture is featured on the cover of Bridge Carney's "First Up"

Hope this helps.

Wayne


Total Posts: 247 | Joined: Oct 11, 2006 - 5:40am | IP Logged

Bob Butler

MASTER
  

    
Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Bob Butler  Posted on: Apr 30, 2013 - 12:25pm
Thank god we got an answer!!!


Total Posts: 192 | Joined: Mar 23, 2013 - 11:58am | IP Logged

  Drew Cook

TOP BOSS
  

    
Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Drew Cook  Posted on: Apr 30, 2013 - 2:47pm
OK -- so they're "bridles," not "bras!"


Total Posts: 1241 | Joined: Oct 19, 2006 - 10:44am | IP Logged

Prev Page | Next Page

Pages: 1 2 3 4 [5] 6


Lock Topic

 

Forum Legend

New Member

Reply to topic

More than 25 posts | Full Member

Reply to topic with quoted message

More than 50 posts | Advanced Member

Edit Message

More than 150 posts | MASTER

View profile

More than 300 posts | TOP BOSS

Email member