This was fairly simple: an MSC8 scenery animator to control effects in and around the engine shed at Portsmouth. The unit itself is mounted under the Portsmouth baseboard, and powered by accessory DCC track power. Its outputs are as follows:

Output DCC  Function  CVs 
573     
574  servo: engine shed door   CV10=4; CV54=220; CV55=60 
575  servo: yard gate   
4 576 on/off lighting in engine shed CV12=2
5 577 welding in shed CV13=0; CV21=1
6 578    
7 579    
8 580