Plan and Section of S.Y. 'Aurora'
Of importance second only to a strong hull is the possession of sails in addition to engines. The latter are a sine qua non in polar navigation, whilst sails allow of economy in the consumption of coal, and always remain as a last resort should the coal-supply be exhausted or the propeller damaged.
The 'Aurora', of the Newfoundland sealing fleet, was ultimately purchased and underwent necessary alterations. She was built in Dundee in 1876, but though by no means young was still in good condition and capable of buffeting with the pack for many a year. Also, she was not without a history, for in the earlier days she was amongst those vessels which hurried to the relief of the unfortunate Greely expedition.
The hull was made of stout oak planks, sheathed with greenheart and lined with fir. The bow, fashioned on cutaway lines, was a mass of solid wood, armoured with steel plates. The heavy side-frames were braced and stiffened by two tiers of horizontal oak beams, upon which were built the 'tween decks and the main deck. Three bulkheads isolated the fore-peak, the main hold, the engine-room and the after living-quarters respectively.
A hull of such strength would resist a heavy strain, and, should it be subjected to lateral pressure, would in all probability rise out of harm's way. However, to be quite certain of this and to ensure safety in the most extreme case it is necessary that the hull be modelled after the design adopted by Nansen in the 'Fram'.
The principal dimensions were, length one hundred and sixty-five feet, breadth thirty feet, and depth eighteen feet.
The registered tonnage was three hundred and eighty-six, but the actual carrying capacity we found to be about six hundred tons.
The engines, situated aft, were compound, supplied with steam from a single boiler. The normal power registered was ninety-eight horse-power, working a four-bladed propeller, driving it at the rate of sixty or seventy revolutions per minute (six to ten knots per hour).
Steam was also laid on to a winch, aft, for handling cargo in the main hold, and to a forward steam-windlass. The latter was mainly used for raising the anchor and manipulating the deep-sea dredging-cable.
The ship was square on the foremast and schooner-rigged on the main and mizen masts.