London Transport acquired three examples from an iron ore mine, not new, in 1971. These locomotives were intended to replace pannier tank engines still in operation and would be painted in a similar colour to their predecessors original GWR green. Each of these Sentinel locomotives would find itself coupled to a tender permanently, this tender would take the form of a bogie removed from an old district line stock unit. DL81 would be withdrawn in 1993 alongside it's two sisters and sold in to private use. Following this, it would find itself preserved at Rocks by Rail in Cottesmore.

The Hornby 0-6-0 Sentinel is a recently tooled model and a perfect addition to any small or industrial layout. The model is 6 pin DCC ready allowing for digital operation. The London Transport model features some enhanced detailing such as dumb buffers, NEM pocket covering plates and a prototypical trip cock by the wheelset.