Monday, 19 February 2007

Whaling

There's the remains of a whaling factory at Whaler's Bay on Deception Island in the South Shetland Isles which I examined briefly in February 2007. My distaste for whaling means that I have never previously studied the processing involved but, confronted by this industrial archaeology, I felt the need to consider the operation to help to understand what I was looking at. But I had a mere 30 minutes to look at the site, so I have probably made a number of blunders. My interpretation was greatly assisted by subsequently reading the book cited below.

The blubber and other parts of the whale were cut up and mechanically minced before being placed in large steam pressure cookers called 'digesters', so as to extract the oil which was stored in huge tanks. The remaining solid material was converted into fertiliser.

At Whalers' Bay, the steam was produced by a series of vertical, dome-topped, rivetted boilers with circular section - Cochrane Boilers. The fireplace is at the bottom, with two hinged firedoors, side by side, presumably for coal-firing. At the rear, at low level, there is the remains of what might have been the means of regulating combustion air. Two flat, vertical, parallel tube plates divide off the water space. The two tube plates are conneected by a large number of horizontal smoke tubes. At the front, the curved shell is provided with a large hinged door, to allow access to the tube plate. The inside of this door is provided with a layer of firebrick. There is a similar, but smaller, aperture in the shell at the rear to lead away the exhaust gases. A framework, which was originally plated, is provided around this rear aperture to form the base for a circular, sectional, rivetted, vertical chimney. A plug-type safety valve is provided on the dome top. Relieving pressure is set by a counterweight fixed at the end of a long arm which holds the safety valve plug in place.

There was originally a rectangular tank mounted on a support structure at high level which was presumably the header tank for the boiler feed water. A part-buried Weir pump indicates the likely method of maintaining boiler water level.

I found two different groups of digester tanks, of slightly different sizes. They are vertical, closed cylinders. A rectangilar, hinged manhole is provided on the top for charging, with turnscrews to secure it tightly. I assume that there would have been a high-level walkway and means to get the whale material up to this level for charging the digesters. A reference in the book cited below refers to steam being applied for four hours, after which water would be fed into the digester to displace the whale oil which had been released. A second rectangular, hinged manhole is provided near ground level, again with turnscrews to secure it. Presumably, this was to allow the remaining solid material to be discharged for conversion to fertiliser.

Some yards away from the complex of steam boilers and digesters is a separate fireplace, now largely buried, somewhat similar in appearance to a Lancashire boiler. It is a substantial, rectangular construction of good-quality, red bricks, strengthened by metal banding. One smaller side is provided with a cast front mounting two hinged firedoors, side by side. Internally, the fireplace is lined with refractory bricks.

The most noticeable remaining feature of the factory is the oil storage tanks, because of their size. I am told that internally these tanks are provided with steam heating coils, presumbly to keep the oil sufficiently fluid at the low temperatures experienced.

A well-researched book on whales and whaling is 'The Whales' Journey', by Stephen Martin, published by Allen and Unwin, ISBN 1 86508 232 5.

It has been reported recently that the existing ban on whaling has been weakened. If you believe that the arguments in favour of such weakening of the ban are unconvincing, please add your voice to the call for a complete and effective ban on all forms of whaling.