The Mk38 Gun Mount and Ballistics and Weapons Effectiveness Lessons from Pursuit of the Graf Spee, Part 1

This is the first of a 2 part post by Chuck Hill’s CG Blog.  Part 1 uses The Battle of the River Plate to help explain the difficulties of just stopping a large ship, never mind actually sinking one.

Part 2 shows the potential weapons systems, tactics and difficulties today’s USCG could use to stop a large ship being used for nefarious purposes, either as a weapons carrier or as the actual weapon.

As a naval history buff Part 1 is the most interesting to me but both parts are well worth the time to read.

Photo: Heavy cruiser HMS Exeter seen after the battle, looking aft from the bow. Both forward twin 8″ gun turrets and the firecontrol system were disabled and the bridge destroyed by “splinters.”

 

Admiral Graf Spee in the English Channel in April 1939. U.S. Naval Historical Center Photograph # NH 89566.

Photo: After superstructure of Admiral Graf Spee showing 15 cm/55 and 10.5 cm/65 guns. Note the burned-out Arado Ar 196A-1 floatplane on the catapult and the after main-director rangefinder. Photograph taken at Montevideo, Uruguay in mid-December 1939, following the Battle of the River Plate. U.S. Naval Historical Center Photograph # NH 80976.

 

Introduction:

Note, this has been edited from the original, based on feedback particularly with regard to the ammunition remaining on Graf Spee after the engagement. I don’t believe the thrust of the post has been changed.  

This is the first of two parts. Part one will tell a story. Part two will talk about the implications of lessons learned, applied to how the Coast Guard might deal with the threat of terrorists using a medium to large merchant ship to make an attack.

These are themes that will be discussed in part 2 before looking at specific tactics to make the best use of what we have. Hopefully you will see these illustrated in the following story.

  • In comparing guns, at any given range, the longer ranged weapon generally enjoys an advantage in accuracy.
  • It is very difficult to sink a ship by gunfire alone.
  • Ships’ structure provide a degree of protection that makes it difficult to comprehensively target the crew of a ship without sinking the ship.
  • It is difficult to forcibly stop a ship with gunfire alone.
  • You can run out of ammunition before you accomplish your mission. The depth of your magazine may be important.

 

But first the story: The Mk38 Gun Mount and Ballistics and Weapons Effectiveness Lessons from Pursuit of the Graf Spee, Part 1

 

75 years ago this month

It’s 35 degrees Fahrenheit this morning (it feels like a balmy 40 degrees in the shop) and we’re supposed to have flurries Friday morning.  My blood is too thin for this so here’s a picture to remind me it could always be colder and wetter.  I feel sure the North Atlantic in January qualifies…

U-Boot U-123 in See

The forward gun crew of U-123 prepare to engage a surface vessel sometime in January 1942.

U-Boot U-123 in See

This view from the conning tower of U-123 shows their intended victim in the distance.

via: http://ww2today.com/

More on U-123

71 years ago today

navy_day_1945_ships_hudson_river_ny

Tugboats and U.S. Navy warships pictured in the Hudson River with the New York City skyline in the background for the Navy Day celebrations on 27 October 1945. Visible in the foreground are the anchored warships USS Augusta (CA-31), USS Midway (CVB-41), USS Enterprise (CV-6), USS Missouri (BB-63), USS New York (BB-34), USS Helena (CA-75), and USS Macon (CA-132) U.S. Navy – U.S. Navy National Museum of Naval Aviation photo No. 2001.256.009

HMS MTB-263 (Motor Torpedo Boat)

HMS MTB-263 (British Motor Torpedo Boat, 1940, ex-USS PT-14) Ready for delivery to The Royal Navy, circa Mid-1941. She has been modified to British specifications, with R.N. Type 21″ Torpedo Tubes, a 20mm machine cannon and other changes. (NHHC: NH 100911)


70′ Motor Torpedo Boat:

  • Laid down 26 April 1940 as PT-14 by the Electric Boat Co., Elco Works, Bayonne, NJ
  • Launched 7 November 1940
  • Placed in service 29 November 1940 and assigned to Motor Torpedo Boat Squadron TWO (MTBRon 2) under the command of Lt. Comdr. Earl S. Caldwell, USN
  • MTBRon 2 tested the first 70′ Elco boats in Florida and Caribbean waters in the winter of 1940/41
  • Transferred to the Royal Navy as HM MTB-263 11 April 1941 and assigned to the 10th MTB Squadron
  • Returned to U.S. Navy 16 March 1946 at Alexandria, Egypt
  • Transferred to the State Department, Foreign Liquidation Commission in December 1946
  • Fate unknown.Specifications:
  • Displacement 40 t.
  • Length 70′
  • Beam 19′ 11″
  • Draft 4′ 6″
  • Speed 41 kts.
  • Complement 15
  • Armament: Two twin .50 cal. Browning M2 machine guns in Dewandre turrets and four 18″ torpedoes
    (MTB-263 added two .303 cal. twin Mk1 Lewis machine guns, one 20mm mount and two depth charges in addition to replacing the 18″ torpedoes with two 21″ torpedoes)
  • Propulsion: Three 3,600shp Packard V12 M2500 gasoline engines, three shafts.

via  NavSource