Total-loss oiling system

A total-loss oiling system is an engine lubrication system whereby oil is introduced into the engine, and then either burned or ejected overboard. Now rare in four-stroke engines, total loss oiling is still used in many two-stroke engines.

Steam engines used many separate oil boxes, dotted around the engine. Each one was filled before starting and often refilled during running. Where access was difficult, usually because the oil box was on a moving component, the oil box had to be large enough to contain enough oil for a long working shift. To control the flow rate of oil from the reservoir to the bearing, the oil would flow through an oil wick by capillary action, rather than downwards under gravity.

On steamships that ran their engines for days at a time, some crew members would be "oilers" whose prime duty was to continuously monitor and maintain oil boxes.

On steam locomotives, access would be impossible during running, so in some cases centralised mechanical lubricators were used. These devices comprised a large oil tank with a multiple-outlet pump which fed the engine's bearings through a pipe system. Lubrication of the engine's internal valves was done by adding oil to the steam supply, using a displacement lubricator.

The first recirculating systems used a collection sump, but no pumped circulation, merely 'splash' lubrication where the connecting rod dipped into the oil surface and splashed it around. These first appeared on high-speed steam engines. Later, splash lubrication engines added a 'dipper', a metal rod whose only function was to dip into the oil and spread it around.

As engines became faster and more powerful, the amount of oil required became so great that a total loss system would have been impractical, both technically and for cost.

Splash lubrication was also used on the first internal combustion engines. It persisted for some time, even in the first high-performance cars. One of Ettore Bugatti's first technical innovations was a minor improvement to the splash lubrication of crankshafts, helping to establish his reputation as an innovative engineer.

...
Wikipedia