The thorn gamma 3 is a rare lantern. They could run 250-400w MBF, 400w MBI/F or 250-400w SON. They are almost always remote-geared and the lamp is sitting vertically inside of the lantern. 

Sainsbury’s car park, chertsey, surrey

These thorn gamma 3s are in the Sainsbury’s car park in chertsey, Surrey. They run on a SON lamp.

one of the column doors is taped up. This picture was taken about an hour later than the other picture.