hydrostatic and mechanical lubricators but it was best-known for its patent mechanical lubricator. Marketed as the Wakefield Lubricator it comprised a large oil chest (typically for eight delivery tubes) with eccentric-operated pumps submerged within it. Regulation of the oil feed was achieved by adjustment of sleeve valves, which could be made to release oil back into the reservoir (instead of entering the feed tubes) at varying stages as the delivery stroke progressed. If the device were used to deliver heavy grade oil to the steam cylinders the reservoir was heated by a steam coil to allow the oil to pass more easily down the delivery tubes. Silvertown mechanical lubricator The Silvertown lubricator was designed and developed by the Midland Railway in 1911 and from 1922 was commercially available from Gresham and Craven. This style of mechanical lubricator was used by the London, Midland and Scottish Railway and latter by British Rail, as well as by the various UK private locomotive builders for export overseas. Commonly 2 lubricators were fitted, one for lubricating the cylinders and the second for lubricating the axleboxes. The lubricator is a self-contained unit with the drive mechanism fitted at one end, with the drive shaft running through the cast iron oil reservoir. The drive shaft is fitted with 2 hardened steel eccentrics which provide movement to the drive frame which runs in machined grooves in the oil reservoir. This drive frame reciprocates vertically which then drives the double acting independent oil pumps located in the oil reservoir. The lubricator is driven by a rod from the expansion link in locomotives valve gear. The rocking motion of this drive is converted to a rotary motion by a series of driving pawls contained in a clutch box. The lubricators were also fitted with a priming hand wheel on the outer face of the lubricator. Friedmann/Nathan mechanical lubricator The Friedmann system of mechanical lubricators included the DV & FSA type lubricators. This style of mechanical lubricator was designed & produced by Alex Friedmann KG of Austria. The DV type were then made under licence by in the US by the Nathan Manufacturing Co. & the type DV & FSA types in the UK by Davies & Metcalfe Ltd. Both types of lubricator are of the 'valveless' type, having no ball valves, springs or oil seals used in the operation of the pump units. The DV range was available in