FIRST A CORRECTION: In part VIII of this article an error appeared in the size given for the keel bolts. The ballast keel of the Rother is in fact fixed with 12mm bolts.

The photographs on this page show work progressing on closed circuits needed in a lifeboat to make sure that, come what may, sea water will not penetrate the hull or machinery.

Fig. 1 is another view of one of the propeller tunnels, this time with the stern gear in place: naval brass sleeve piece forward and A bracket aft carrying between them the stern tube through which will pass the propeller shaft. The shafts will need continuous lubrication with very heavy oil, and this calls for the first closed system.

The oil is piped from the after end of the engine room, through a hole in the outboard arm of the A bracket, forward through the stern tube to the forward bearings and thence back into the engine room. When the propeller is turning the oil circulates naturally; when the time comes to change the oil, it can be pumped round with a hand pump.

Fig. 2 is a photograph taken looking down into the forward well and through the open bulkhead into the forward end box. Down in the bilges are twin engine water coolers, one for each of the lifeboat's twin engines; the engines are cooled by fresh water circulating continuously in an enclosed system, while the fresh water in its turn is cooled by sea water. Fresh water coming back hot from the engines circulates through small pipes inside the coolers. Round these pipes, within the outer casing, flows an endless supply of cold salt water; it is taken in forward and expelled out into the sea again through skin fittings in the hull, remaining completely isolated on passage and doing its work, as it were, by remote control.

On the sides of the well at the forward end, port and starboard, are aluminium vent trunks; evidence of yet another closed circuit. This time it is a ventilation system which will keep wood in sealed compartments of the hull in good heart. Air coming from aft through the wing compartments is routed through these aluminium trunks into the lower part of the forward end box. From there, the air is vented through pipes to the upper part of the end box from where it is driven by fans back through pipes to the engine room.

(To be continued).