Trackmaster was a clockwork system which were taken over by Triang in their search for rolling stock in the early days. Not only did Trackmaster wagons continued to be produced by Triang, they kept the same running numbers on the wagon sides.
Trackmaster wagons had closed axle boxes. Many wagons are found today with Hornby Dublo or Triang chassis. This is because in the last year of Trackmaster they stopped selling chassis and only produced the plastic bodies (due to metal shortages during the Korean War).
The only locomotive that Trackmaster produced was the N2, which Triang took over as the R51. I do not have one yet, but it is on my wants list.
Triang could not use the track as it was one piece metal and it is difficult to find today.
A late Trackmaster produced body with original grease proof paper. This was the time when Trackmaster stopped producing wagon chassis. Of special note, the box is stamped "BODY".
Really the track could only be used with clockwork systems, however, I have run a Triang electric loco on the track using the catenary for the second power feed. Harrow Park does have a siding of Trackmaster track, it is used as a storage track for clockwork locomotives. Trackmaster were made by Pyramid Toys.