BASE : Of 1 5.25m (50 ft 0 in) diameter, built-up of rolled plate welded and braced to support the main 13 m (42 ft 8 in) diameter roller path of special nickel chrome molybdenum steel segments, together with the special heat-treated rotate gear rack with 176 machined teeth 8.54m (28 ft 0 in) p.c.d. The live ring consists of 120 alloy steel 254mm (10 in) mean diameter rollers mounted in heavy bar inner and
ROTATE FRAME: This is made up of rolled steel plates and flats welded to form four longitudinal girders 3.14m (10 ft 4 in) deep, into which is built the circular girder to carry the roller path.
WALKING GEAR : This consists of a I 7.Om x 2.8m(55 ft 9 in x 9 ft x 2 in)rectangular walking shoe on each side, lowered to ground level by eccentric motion derived from the walk machinery. The walking drive consists of two separate motor-driven units electrically synchronised with Selsyn units. The shoes are suspended from the rotate frame by the eccentrics and walking legs, the former a fabricated structure which houses the live ring and bearings for the walk tubes, the throw is 0.6m (2 ft 0 in) giving a walking step of 2.28m(7 ft 6 in) and a walking speed of 0.24kph(0.1 5mph).
HOIST AND DRAG UNITS: These units, of identical design except for drum grooving, are independent and mounted on the machinery deck. On each unit 2 motors of l300hp drive the drum through helical gears. The drums are arranged for twin rope winding. Parking brakes are provided on each motor. Maximum line pulls at stall 189.921-255.608 kg(418.704-563.519 Ib). maximum Line speed, no load 160-222 mlmin (525-728 ft/mi line speed payout 220-274 m/min(722-889 Wmin) dependent on drum size and gear ratios.