Midland Railway Centre - Caprotti Crescendo. A mini gala to mark the end of No. 73129's 10 year boiler ticket. This was to be its last weekend in steam for some considerable time. The only surviving Class 5 built by British Rail with Caprotti valve gear. This is an Italian design of rotary cam poppet valve gear that is efficient and light to operate. The locomotive was outshopped in 1956 and was one of 30 'Black 5s' fitted with Caprotti gear.