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These monitors were originally known as M1, M2, M3 and M4, then redesignated as Admiral Farragut, Robert E. Lee, Stonewall Jackson and General Grant (showing their USA heritage), but US diplomatic protests meant that they finally entered service as Abercrombie, Havelock, Raglan and Roberts. Eight of these guns were built to the Bethlehem design and consisted of a thin A tube and three layers, each of three tubes. The breech bush screwed into the outer two tubes and the hand-operated breech mechanism resembled the British Elswick type. The outer tubes were apparently not locked together very well and the guns drooped for the first few salvos until they warmed up after which they locked together properly. A further two guns were built by Woolwich as spares and were also designated as Mark II. These were to standard British wire wound construction standards but kept the same external contours as did the Bethlehem guns. These two guns were used to regun Abercrombie in May 1918. The Bethlehem mountings were electrically powered and quite unlike anything built in Britain. After their re-erection and check-out problems were corrected, they proved to be very reliable in service. The two Bethlehem Mark II guns removed from Abercrombie in 1918 were closely examined by the British ordnance experts at Woolwich. The British were not impressed by the construction of these guns, noting that their poorly locked hoops and thin A tube gave them a low degree of safety. The general conclusion reached was that there was no particular advantage to copying USN practice in naval guns, mountings or propellant. Although the British were unimpressed with their overall design, these mountings did perhaps perform better under fire than did contemporary British designs. In January 1918, HMS Raglan was holed through the barbette by a 28.3 cm (11.1 in) shell from the former SMS Goeben, now the Turkish Yavuz Sultan Selim. This hit ignited charges in the hand-up chambers between the handling rooms and gunhouse, but the flash was contained and did not spread below to the magazines. This may also have been due to the fact that the propellant was USN nitrocellulose and not British cordite. Late in World War I, British cordite was substituted for the US nitrocellulose propellant originally supplied. This resulted in a substantial loss of muzzle velocity and a matching reduction in maximum range. The 14"/45 (35.6 cm) Mark IV designation was given to two ex-USN guns provided as spares for the Abercrombie class but never used. These were similar to the Mark II but built with a very thin inner "A" tube and with the outer tubes properly locked together. Two further USN guns were provided and designated as Mark V, as these used an Asbury roller cam breech mechanism. None of these Mark IV and Mark V guns were ever used. As all of these guns were built to USN standards, their bore length by British standards was 44.5 calibers. The data that follows is specifically for the 14"/45 (35.6 cm) Mark II. |
Unidentified Abercrombie Class Monitor
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