R.R.S. 'DISCOVERY IT 91 



The oil-fuel installation is of the Wallsend-Howden type working in conjunction with 

 Howden's forced-draught system. The oil-fuel pumps are of Messrs Weir's horizontal 

 simplex type working in conjunction with Wallsend heaters. The forced-draught fan is 

 fitted at upper-deck level in the engine room. It discharges to the boilers through a duct 

 leading between the boilers, giving an equal distribution of air to each boiler. This 

 arrangement of fan is found beneficial in assisting the ventilation of the engine room, 

 and does not possess the disadvantage of being open to the stokehold. 



A special feature in the machinery installation is the lagging of boilers and pipes. This 

 is arranged not only to prevent condensation and heat losses, so far as may be possible, 

 but also as a protection against freezing at the low temperatures in which the vessel is 

 working. The general thickness of lagging on steam pipes is about ih in., while on the 

 boilers it is 3 in. The lagging makes the engine room and stokehold extremely com- 

 fortable under all conditions of working. 



There is a small workshop at the port after end of the engine room. It is par- 

 titioned off from the engine room by a half-steel bulkhead, with expanded wire netting 

 in the upper parts, so that the shop can be completely closed. The ohop contains a 6-in. 

 screw-cutting lathe of Messrs Drummond's make, a small shaping machine and a high- 

 speed sensitive drill, in addition to a 12-in. diameter emery wheel. The usual equipment 

 of benches, vices, shelves, lockers, etc., is provided. The whole of the machinery in the 

 workshop is driven by an electric motor. 



The electrical equipment consists of two independent generating sets. The larger set 

 is capable of supplying power for the whole of the electrical equipment in the ship ; the 

 smaller set is intended for harbour use and general service, when lighting only and small 

 calls on power are required. The larger generator has an output of about 28 kw. at no 

 volts and is directly coupled to a compound two-crank steam engine of Messrs Sisson's 

 make, the cylinder sizes being 6i and 9 in. with a common stroke of 5 in. This generator 

 can supply current simultaneously for the whole of the lighting, fans, searchlight, wire- 

 less, refrigerator, workshop motor, floodlights on derricks and other electrical require- 

 ments. The smaller generator has an output of about 10 kw. at no volts, and is also 

 directly coupled to a compound single-crank steam engine of Messrs Sisson's tandem 

 type. 



A large switchboard, of the enclosed type, is fitted at the level of the main-deck 

 stringer, where it is well sheltered and all parts both back and front are readily acces- 

 sible. The connections at the back of the board are all open and capable of being readily 

 examined when required. The whole installation was carried out by Messrs J. Charters 

 of Glasgow, and it has given very satisfactory service. 



A full equipment of spare gear is provided for the main and auxiliary machinery, in- 

 cluding spare propeller shaft and spare propeller blades. 



The ship has a large bunker capacity -,316 tons of fuel oil are carried in bunkers which 

 are divided by three fore and aft oiltight divisions into two main and two wing com- 

 partments. The usual subdivision of oiltight transverse bulkheads and fore and aft wash 

 plates was not adopted for this ship, the arrangement fitted being considered safe in the 



