Palmerston North Electric Power Station Inc.

The British Polar Engine - some background

PNEPS Inc. has only just begun researching the company, nowadays called British Polar Engines Ltd., of Govan, Glasgow, Scotland, that produced our two K48M engines. Clearly, there is considerable work on the topic remaining to be done. Some details that are known, however, are reproduced here.

The Oil Engine Manual, published in 1941, recorded that British Polar engines were manufactured in Glasgow, Scotland, by British Auxiliaries, under license granted by the Swedish Atlas Company. All were "direct-ignition single-acting two stroke units, with a piston pump or rotary blower for scavenge air, driven from the crankshaft. There were three ranges, of 48 b.h.p., 105 b.h.p. and 192 b.h.p. per cylinder at speeds of 600 r.p.m, 425 r.p.m and 300 r.p.m, respectively." The section then goes on to provide more technical detail of the engines then in production.

The book British Diesel Engine Catalogue (Fourth Edition - 1957) described British Polar engines as being "of the two-cycle type, built under license from Nydqvist & Holm, Trollhattan. The first Polar two-cycle engine was installed in a sea-going vessel in 1907. The first motor vessel to cross the Atlantic was powered by a Polar engine - the year 1911. At about the same time the Fram was conquering the South Pole, and it is from that successful Amundsen Expedition that the engine derives its name.

"Many other ships have made history with Polar engines including the Girl Pat, the Rescue Tugs Bustler, Turmoil etc., and of course the M.T. Theron chosen for the 1956 trans-Antarctic expedition.

"The development of Polar engines has been a continuous process over the years and has resulted in reliability in an outstanding degree. The basic design of the modern British Polar engine with airless injection was introduced in 1928. It was an immediate success: reliable, economic, easy to manoeuvre and remarkably simple in design and construction. This early design has been developed and extended to a wide range of engine sizes covering powers from 300 b.h.p. upwards to 4,000 b.h.p. without supercharging.

"To meet the increasing demand for British Polar engines, the works have been extended and reorganised in accordance with the most modern practice. Many new general and special-purpose machine tools have been installed and the whole layout has been arranged to provide a continuous flow of engine components through the machines to the assembly bays. Extended inspection, testbed and storage facilities contribute to increased output of finished engines and to ensure first-class work. Visits to the works by responsible persons interested in Diesel engines or modern production methods are (as at 1957) welcomed."

The detailed article then goes on to describe the general specifications of British Polar engines, including the marine engines. Also shown are photos of small ships powered by British Polar engines and three K48M engines installed at the North of Scotland Hydro-Electric Board's Kirkwall Power Station (pictured below).

Some detail is known of the two Palmerston North engines prior to their departure from Scotland. The June 1935 issue of the monthly magazine, The Oil Engine, outlined "Some Big Oil-engine Contracts," and amongst these, on p. 41. was the following: "As an extension to the existing power station at Palmerston, New Zealand, two generators have been ordered, each to be driven by a 1,400 h.p. Polar oil engine, constructed by British Auxiliaries, Ltd." Page 68 of the same issue repeated the order placed with British Polar.

The front page (p. 133) of the September 1935 issue of The Oil Engine recorded how throughout the world diesel engines were becoming popular as replacements for steam for power generation. An important example cited in the article was: "At Palmerston North, New Zealand, the City Council has for years purchased electricity in bulk from a big power board, corresponding somewhat to our Grid system. The Council now considers that it can more cheaply generate its own electricity, and has just ordered two 1,000-kw. British Diesel-engined generating plants for the purpose."

In their March 1936 issue (p. 345), The Oil Engine published another article on our engines. This reminded that: "Some time ago two 1,400 b.h.p. British Polar Diesel engines were ordered by the Palmerston North City Council (New Zealand), and an illustration of one of these units (shown above) is now given. It is of the two-stroke single-acting Polar type with eight cylinders. In trials the fuel consumption was 0.38 lb. per b.h.p. hour."

We cannot, unfortunately, be certain which of our engines this is. However, the same photo appeared in the aforementioned 1941 book The Oil Engine Manual. There the caption stated that it was a 1,536 b.h.p. eight-cylinder engine, running at 300 r.p.m.

Some of the interior layout of the engine, from The Oil Engine Manual, p. 147. Note that the grey blotches are scanning flaws and in fact there is nothing but the obvious lines shown in those areas.

Last updated: 1/4/2001


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