Brock’s WW1 Munitions

Frank Arthur Brock, son of Arthur Brock of Haredon, Sutton.
(Nephew of C.T. Brock)
Born: 29th June 1888, Cheam, Surrey, England.
Died: 23rd April 1918, St George’s Day, (aged 29), Port of Zeebrugge, Belgium.
Wing Commander Royal Naval Air Service 1914–1918, Zeebrugge Raid.
UK OBE 1917 military BAR.svg Order of the British Empire.
Victory Medal MID ribbon bar.svg Mentioned in dispatches.

Wing Commander Frank Arthur Brock, RNAS


Wing Commander Frank Arthur Brock OBE was a British officer of the Royal Air Force who devised and executed the smoke screen used during the Zeebrugge Raid on 23 April 1918, in the British Royal Navy’s attempt to neutralize the key Belgian port of Bruges-Zeebrugge during the First World War.
Member of the Admiralty Board of Invention and Research and founded, organized and commanded the Royal Navy Experimental Station at Stratford.

In an extract from ‘WINGLESS SAILOR’ By Sidney Hesse (Royal Naval Air Service)
Hesse recalls:-
“The Royal Marines landed on the Mole, and they had no cover – it was all wharf.
Some that went ashore were killed. My CO, Wing Commander Brock, was on the Vindictive as one of the landing party. He went ashore and he was killed going along the Zeebrugge Mole, and so was the man with him. Brock was drunk too, but he probably  knew more than I did about what was going to happen!”

Tuesday, 23rd April 1918
Frank Arthur Brock, dies, St George’s Day, (aged 29), Port of Zeebrugge, Belgium.

As reported by Vice Admiral Gordon Campbell, VC, DSO.
After the Zeebrugge Raid, April 1918, H.M.S Vindictive returned to Dover under her own steam. The cruiser played an active part during the operations at Zeebrugge and her officers and men displayed extraordinary heriosm. Many of them were killed during the action. After the Bruges Canal had been blocked, the Vindictive withdrew.


Brock VIIK Mark I

Designed by Wing Commander Frank Arthur Brock, RNAS ((Royal Naval Air Services).
The Brock explosive bullet was first developed in .45 inch calibre using a .45 inch Express rifle. It was trialled by the Admiralty and they sponsored the development of a .303 inch version for use by the Royal Naval Air Service.
‘Cartridge S.A. Incendiary BIK .303 inch (VIIK) Mark I’ was approved to design IDW 3418 in late 1916 for Naval Service. The tile was changed in 1917 to ‘Cartridge S.A. Ball BIK .303 inch (VIIK) Mark I’.
It utilised a normal Berdan primed case, and whilst the official drawing showed the headstamp to include the code “VIIK” all known examples have a normal ball headstamp.
A blue primer annulus was approved in June 1918 but by then production had ceased.


The bullet had a cupbrock-nickel envelope with a hole in the nose 0.09 inches wide. The lead antimony core had a .8 inch deep nose cavity into which the main composition was placed with an air channel running through the centre.On top of this was the priming charge which protruded through the envelope and was covered by orange varnish. The bullet weighed 149 grains and had one cannelure.
The bullet is seated deeply to give a short overall cartridge length and is secured by three indents low down the cartridge neck.
The main composition was potassium chlorate and the priming mix was potassium chlorate and mercury sulphocyanide.
The propellant was 37.5 grains of Cordite MDT 5-2 with one wad.
Muzzle velocity was about 2,380 fps.


BROCKS DART (Anti Zeppelin Incendiary Flechette)

12th August 1915 – Brock’s submition to Munitions Inventions Dpeartment.(transcript).

                          MUNITIONS INVENTION DEPT.
                           MINISTRY OF MUNITIONS

                           COPY FOR DRAFTING ROOM

         SUBJECT:- SPECIAL BROCK ZEPPELIN DART. For evaluation by Royal Flying
                   Corps. Technical Section. Aldershot. For approval and
                   acceptance in List of Changes in War Material.

         Submitted by:- C.T. Brock & Co. Sutton Surrey. An incendiary and or
                        incendiary/explosive dart for hand release when above
                        zeppelins or other dirigeables. Designed by Commander
                        F. Arthur. Brock. R.N.V.R.

         Description:- Round conical point four inches long and three eigths
                       of an inch in diameter, affixed to this a brass tube
                       of same diameter with three small fins attached to
                       rear end for stabillity, the brass tube will be stamped
                       C.T. Brock SBZD and will carry the charge.

         In trials conducted by the R.N.A.S. at Fort Grange Gosport on 26/6/15
         with the board of Navel Ordnance in attendance the following charges 
         were used:-
                    I/. White Phosphorus/Aluminium Powder.
                    2/. Tungsten/Phosphorus mixed 80/20 and centre portion to
                        be charged with N.P.E. (nitronentaeythite) or Guhr
                        Dynamite of 75% nitroglycerine.
                    3/. 74% Potassium chlorate 13% Red Lead Oxide. 13% Salicylic 
         To prevent oxygen contacting with the charge the end will be closed
         with a brass disc and removable air tight cap, the cap would have to
         be removed by the Pilot/Observer before release.

             The special brock zeppelin bullet has been very successful
             when used on zeppelins also the Pomeroy and Buckingham.
             Companys who could assist in the productionof the zeppelin 
             dart are as follows:- 
                                 Kings Norton Metal Co.
                                 Nobels Explosive Co.
                                 Eley Bros.

                      All Depts.

W.D.O. (A)
12. August 1915

12th August 1915 – Brock’s submition to Munitions Inventions Dpeartment.(scan).


Special Brock Zeppelin Dart
Items similar to these were dropped from high altitude onto the enemy trenches, with devastating results.

An Ariel dart designed to be used as a counter measure against the Zeppelin airship.
The weighted dart would have contained a phosphorus mix in the hollow centre tube section.
This would have burned on contact with the air and was to be dropped from an aircraft above the Zeppelin.

 ‘C.T.BROCK  SBZD’ (Special Brock Zeppelin Dart).




The objective target of the ‘Special Brock Zeppelin Dart’.


Last Update: 2nd Feb 2017 @ 14:19

3 thoughts on “Brock’s WW1 Munitions

  1. Philip Simpson December 8, 2017 / 3:28 pm

    Hi Freddy,

    Would you mind me asking where the image of Frank was sourced? Im looking for a good Image of him for a small exhibition in Cheam.

    Thanks Philip


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