Anybody who is familiar with Tilley lamps will understand that the provision of these at unstaffed halts would be less than straightforward. Tilley lamps are paraffin lamps which operate under pressure and use incandescent mantles. The fuel is forced from the tank by air pressure up to the vapouriser where it is turned into a gaseous form prior to burning. The vapouriser operates by the heat of the mantle but this means that when cold it has to be preheated. This is done with a preheating torch filled with wadding and soaked in methylated spirit. Preheating takes three or four minutes and at the same time the fuel tank has to be pressurised using an integral pump. Once the preheating flame begins to subside, the vapouriser should be hot enough to do its job; a valve is then opened to send fuel into the vapouriser and the lamp should fire up. After the mantle has been burning for a couple of minutes, the fuel tank can then be pumped up to full pressure and the lamp should run for as long as there is fuel in the tank and there are no pressure leaks. That is the theory anyway; as air pressure drops inside the tank it is in part compensated for by the tank itself becoming warm, but to maintain a constant bright light over a long period the air pressure needs topping up occasionally.
Tilley lamps in their various forms were once widely used by the railways, including London Transport. Perhaps the most famous were the 'Challow' lamps for use at that former Great Western Railway station. In the 1930s Tilley produced their model PL55 and in 1949 the BR49 model was introduced especially for British Railways but was also available to the public. The main difference was that the PL55 and BR49 used a paraffin preheater and so did not require methylated spirit. The drawback, however, was the necessary provision of two fuel cocks (standard Tilley lamps had one) which had to be operated in a particular order; fuel-to-preheater open and fuel-to-vapouriser closed, then when preheating was complete the reverse applied; fuel-to-preheater closed and fuel-to-vapouriser open. These lamps were equally as time consuming to start as the spirit preheated versions. Three or four minutes may not sound a lot but when we consider claims that these lamps, supposedly used at unstaffed halts, were supposedly the responsibility of train guards then three to four minutes per halt would be totally impractical. Two lines with unstaffed halts where Tilley lamps are claimed to have been used are the Mildenhall and Saffron Walden branches. In both instances no photographic evidence of Tilley lamps has been seen but photographs of oil lamps (that is, wick lamps) in use at the time of closure, or very shortly before closure, have been seen.
It might be suggested guards prepared Tilley lamps for unstaffed halts onboard the trains but there is no evidence this was the case and it would certainly not have happened where diesel railbuses were in use. In any event, a guard who has to check and issue tickets, handle parcels and other items would not want paraffin residue on his hands. It is also unlikely, even half a century ago, that the firing-up of Tilley lamps, which can be dangerous under certain circumstances, would have been permitted on passenger trains even if it was in the guard's compartment. All these drawbacks are notwithstanding the extra time it would have occupied over and above guards' normal duties.
As we have seen, Tilley lamps were used by the railways and for a range of applications including illumination of staffed stations but claims they were used at unstaffed and often remote halts are open to serious doubt.