5.25-inch Mk III - sketch design of mounting with telescopic hoists

5.25-inch Mark III mountings, Elswick Works, Newcastle-upon-Tyne, 26th October, 1948

Drawing No. 42294 (horizontal stowage)
Drawing No. 46006 (vertical stowage)
Drawing No. 42292 (articulated telescopic pusher hoist)

Top/Plan view (42294)

Elevation: 90°
Depression: 10°
Diameter Roller Path: 19’-0”
Rate of Fire: 48 rounds/minute H.A.
Rate of Fire: 24 rounds/minute L.A.
Weight of Oscillating Parts (2 guns): 25 tons
Weight of Turntable Structure etc.: 40 tons
Weight of Hoists: 18 tons
Weight of Gunshield (½”): 13 tons
Total Revolving Weight: 120 tons

Weight of Magazine Machinery: (H: 40 tons / V: 30 tons)
Weight of H.A. rounds in magazine: (H: 51.5 tons - 750 / V: 43 tons - 628)
Weight of L.A. rounds in magazine: (H: 8.25 tons - 120 / V: 6.33 tons - 92)

Each gun has 2 HA hoists and 1 LA hoist attached from the upper point to the cradle and the lower portion swings about a common trunnion at the base of the mounting structure.

Side view (42294)

Data taken from table of mounting sizes and table of powers

Size	Cals	L/M	Round	Shot	MV	Roller Dia	Gunhouse Height	Revolving Weight
W / d³ = .65			Weight (lb)
4.5	50	L	111	59	2300	18 - 6	9 - 0	87
4.5		M	109	59	2300	17 - 6	9 - 0	82
5.0		L	151	81	2300	20 - 6	10 - 0	112
5.0		M	148	81	2300	19 - 0	10 - 0	103
5.5		L	200	108	2300	22 - 6	10 - 9	132
5.5		M	197	108	2300	20 - 0	10 - 9	127
4.5	70	L	131	59	2700	19 - 0	9 - 3	95
4.5		M	128	59	2700	18 - 0	9 - 3	92
5.0		L	178	81	2700	21 - 0	10 - 0	122
5.0		M	175	81	2700	19 - 6	10 - 0	120
5.5		L	237	108	2700	23 - 0	10 - 9	148
5.5		M	233	108	2700	21 - 0	10 - 9	142
W / d³ = .4
4.5	50	L	88	36	2900	17 - 6	9 - 0	82
4.5		M	86	36	2900	17 - 0	9 - 0	74
5.0		L	120	50	2900	19 - 0	10 - 0	106
5.0		M	117	50	2900	18 -0	10 - 0	100
5.5		L	158	66	2900	20 - 0	10 - 9	122
5.5		M	155	66	2900	19 - 0	10 - 9	119
4.5	70	L	108	36	3300	18 - 0	9 - 0	88
4.5		M	105	36	3300	17 - 6	9 - 0	80
5.0		L	147	50	3300	19 - 6	10 - 0	113
5.0		M	144	50	3300	18 - 6	10 - 0	110
5.5		L	195	66	3300	20 - 6	10 - 9	134
5.5		M	191	66	3300	20 - 0	10 - 9	128

Source: DS.VA/6/25/17