- The Dustman
- Early warships, Naval technology
- RAN Ships
- HMAS Melbourne I
- March 1981 edition of the Naval Historical Review (all rights reserved)
ON 22ND MAY 1912, a 6 inch gun with the number 2285 stamped into the breech ring was proof-fired at Woolwich, United Kingdom. The gun was one of a batch of eight built for the Australian light cruiser Melbourne, at that time under construction at the Birkenhead yard of Cammell, Laird. As was usual at that time a document officially known as a ‘Record of Examination’ was issued by the Woolwich Arsenal, and this record followed the gun throughout its service life. The Record of Examination was often known as the ‘tube history sheet’.
Each time the gun was fired, an appropriate entry was made in the Record of Examination, but the total number of rounds for each day only were recorded. This total is recorded as efc’s, equivalent full charges. During practice shoots it is normal to fire with reduced charges, as this is considered to be the best way to prolong barrel life. The estimated life of the barrel in this case was in the vicinity of 600 rounds, but this does not mean that 600 rounds only could be fired. The life of the barrel was estimated with efc’s, and a scale was worked out whereby 16 half charges could be fired before 1 efc was recorded. If the gun was continually firing half charges it was quite possible for the gun to outlast the life of the ship. This seems to be the case with 2285 EOC.
No. 2285 was a wire wound gun of the breech loading type, its official title being ‘Ordnance, BL 6 inch, Wire, Mark XI’. It was sent to Woolwich for examination and proof firing before being issued to the ship. The proof firings consist of a series of rounds fired from the gun, including at least one round fired with a heavier than service full charge. All the test pressures and muzzle velocities obtained were recorded and each proof round was rated as being equal to 2 efc’s. The gun is normally fired from a proof mounting, and not the mounting that will carry the gun in the ship.
On 22nd May 1912, No. 2285 EOC successfully passed proof and was ready for issue to HMAS Melbourne. On 8th November 1912, the first shipboard firings were carried out in Melbourne, 4 efc’s being recorded. This would have been the first time that the gun was fired in its own mounting. No. AN 6.
From the tube history sheet for No. 2285 we can follow the life of the gun with reasonable accuracy, and we can see how the gun is standing up to service treatment. Every series of 25 efc’s requires the gun to be examined for flaws in the metal and evidence of cracking. The first entry in the examination column appears on 18th May 1915, and this records that No. 2285 was examined and that the bore and chamber were clear. The total efc’s was recorded as 40. That the gun saw very little use is borne out by the fact that when the entry of 2nd July 1914 is checked we find that at that date a total of 38¼ efc’s had been fired. Eight months of war service had only added a mere one and three quarter efc’s to the total. This would indicate about twenty practice rounds. Indeed, during the entire period of the Great War, No. 2285 only fired 134 efc’s, and as Melbourne does not seem to have been heavily engaged at any time, we would be probably correct in assuming that all those shots were in fact practice shots.
When new the muzzle velocity was estimated to be 2,800 feet per second. As the number of rounds fired increased, so the muzzle velocity was deemed to reduce by wear, and adjustment is made to the estimated mv. This is essential so that the sights of the gun can be correctly set. By August 1922, after ten years of service the muzzle velocity had been adjusted to 2,780 fps.
The year 1923 seems to have been a busy time for Melbourne’s gunnery department, as another 55½ efc’s were added during the year.
And so it went on, each year the gun was examined and inspected for wear, and each year the annual gunnery shoots were held, and slowly the total efc’s built up. An entry on 7th June 1927 shows that No. 2285 had fired a total of 328 efc’s since the proof firing in 1912. It is quite evident that the shoot of 7th June 1927 was the last shoot carried out in naval service.