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

 

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

Early torpedo tech

The Brennan torpedo was the first effective guided weapon. Introduced into service in 1887, the Brennan was launched from a shore-side fort and powered by a steam engine which pulled wire off drums in the torpedo. As the wire was pulled in, the drums rotated so powering the propellors that drove it through the water.

Brennan torpedo sites were used to protect the entrances of naval ports. Its major advantages were that if the target manoeuvred, the torpedo could be steered to intercept after launch, by tracking a mast showing above the water. It also carried a large warhead that would strike below the heavy armoured belt. At least 8 Brennan sites have been identified, 5 in the UK and Ireland, 2 in Malta and one in Hong Kong.

Brennan torpedoes had a speed of about 26 knots, well in excess of the speed on the battleships of the time, and a range of 2000 yards. They carried a warhead of 230 (later 364) lbs wet guncotton.

Some details of the Brennan are still secret. The depth mechanism is sealed, and there are no drawings to show how it worked, so the movie shows one of the techniques available at the time. The single remaining original Brennan can be seen at the Royal Engineers museum, Chatham, England.

Animation of 16 inch torpedo, Whitehead design, built by the Royal Laboratories in about 1876. This torpedo has a warhead of 116 lbs (52.5 Kg) wet guncotton, a compressed air compound oscillating engine giving a speed of 9 knots and a range of 1,200 yards (1.1 Km). The animation shows the desk launch carriage that was used when HMS SHAH fired a 16 inch torpedo at the Peruvian armoured turret ship Huascar in 1877. Animation created using Cinema 4D.

Batteries of the HMS Alexandra

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The Development of Navies During the Last Half Century by Eardley-Wilmot, Sydney Marow, Sir, 1847-1929 Published 1892

hms_alexandra_right_elevation__deck_plan_harpers_feb_1886

Right elevation and deck plan as depicted in Harpers Monthly, February 1886

HMS Alexandra was a central battery ironclad of the Victorian Royal Navy, whose seagoing career was from 1877 to 1900. She spent much of her career as a flagship, and took part in operations to deter Russian aggression against Turkey in 1878 and the bombardment of Alexandria in 1882.

She was commissioned at Chatham on 2 January 1877 as flagship, Mediterranean Fleet, and held this position continuously until 1889. She was the flagship of Admiral Hornby in his passage through the Dardanelles during the Russian war scare of 1878. She ran aground in bad weather at the narrowest part of the strait; she was towed off by HMS Sultan in time to lead the squadron to Constantinople. She was present at the bombardment of Alexandria in 1882; in this action the Admiral’s flag was shifted to HMS Invincible, as she was of shallower draught and could sail closer to shore. In 1886, the Duke of Edinburgh hoisted his flag on board, and Prince George of Wales, later King George V, joined as a lieutenant. During this action on 11 July 1882, Gunner Israel Harding flung a live 10-inch shell overboard, an action which led to the award of the Victoria Cross.[1] She paid off in 1889 for modernisation.

In 1891, she was flagship of the Admiral Superintendent of Naval Reserves at Portsmouth, and remained so until 1901. Alexandra was featured in the first volume of the Navy and Army Illustrated in early c. April 1896 and was then described as a “coastguard ship at Portsmouth” with her principal armament being eight 18-tons guns, four 22-ton, six 4-inch and four six-pounder and six three-pounder quick firers.[2] At this time, she had a complement of 408 officers and men and was commanded by Captain W.H. Pigott. Her last sea-time was as flagship of the “B” fleet in the manoeuvres of 1900. In 1903 she became a mechanical training ship, and she was sold in 1908.                                                                    HMS Alexandra

More including pics HERE

Supermarine Walrus

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A Supermarine Walrus in testing, circa 1938. They were carried by most British battleships and cruisers during the Second World War, providing an independent reconnaissance asset. Ungainly as they were these things were actually the first British aircraft to enter service with a fully retractable main undercarriage, completely enclosed crew accommodation and an all-metal fuselage.

via apostlesofmercy