This is a flask train that ran after the Brake Van was no longer required. It is made up of two flasks and two barriers. I saw this train at Ipswich, on its way to Sizewell.
The Flask wagons are by Genesis Kits, a long time before the Bachmann RTR, and the PFA barriers were Hornby chassis, modified as required. All transfers were Fox.
The Genesis kits really went together very well and the castings needed little cleaning up. I used low-melt solder, but they can be assembled with super glue.
These barrier wagons were not the only type used, the most common seemed to have been cut down HEA wagons, although actual HEA’s were used on occasions. No barrier wagons are used now, although all trains have to be double headed.