For CAT 87 some modifications were developed for the FCS on Challenger 1. I think they were incorporated on the tanks taking part but am not 100% sure, this would have meant the crews taking part would have had little experience of the new system. Another problem could have been that the British Army used 3 tank Troops while the others taking part used 4 tank Troops.
The Challenger 1 book by Osprey says that 22 Challenger 1s were prepared specifically for CAT 87 adding Improved Computerised Sighting System, laser sight, and an alternative 15X Commander's sight in the cupola. All tanks modified were delivered by the end of October 1986. The rules had been revisited since the 85 edition and the contestants were to be chosen from one of two regiments per country. The UK put forward Badger Sqn from 2 RTR and B Sqn, Royal Hussars, the latter being eventually picked out of the hat.
The Royal Hussars in 1986 had had to revert to Chieftain being BATUS bound, and that didn't help; nor did the fact that other committments prevented the british team from making use of the 2-days window for reconnaissance of the CAT 87's circuit.
1.9 million was expended for ammunition to be used in training pre CAT-87. 6585 rounds of 120mm were expended, over 500 per crew. That was almost 5 times the allowed amount of 134. While every country played around the rules, and it is well know that some of the other contending regiments trained for 7 months specifically for the CAT, the crews did get good training.
The 3-tank troop was also accounted for in the rules: the 4-tank troops had to hit 32 targets and 80 failing plates; versus 24 and 60 for 3-tank troops, so i'd say that should not have been a factor.
The best score achieved was 16,606, the worst 13,673. The winners scored 20,490.
The RAC Gunnery Wing ran an inquiry into the failure. The use of "prototype" upgrades was deemed to have been a mistake and the quality of training for the competition was called into question, but according to the same book the fundamental causes were identified as:
- 3 piece ammo loading cycle
- complexity, poor ergonomics and unreliability of turret systems
I'm very curious to see how Challenger 2 will do at the Strong Europe, but sadly i would think that the 2-piece ammunition and mobility of Chally will not exactly help the crews achieve great scores.