Airport Installations

The mufflers originally supplied by Cullum Detuners Ltd for use as a fixed installation with Comet aircraft at Heathrow have now been considerably modified and made mobile. Large cylindrical fabrications, 50ft long, 10ft in diameter and weighing approximately 14 tons, they are towed into position behind the aircraft engine for use after engine maintenance operations. Various wheel and castor arrangements were considered, but in view of the requirement for very high manoeuvrability, combined with shock loadings and operating speed considerations it was decided to mount the mufflers on turntable units manufactured by HMC Wheels Ltd. Two 12 ton capacity towable turntable and rear axle units, having a capacity of 24 tons per trailer, were supplied, fitted with 15in. diameter Heavithane wheels. This arrangement was considered most suitable for this type of application where heavy loads are carried at operating speeds of over 5mph over relatively poor surfaces, thus creating high shock loadings. These polyurethane‐tyred wheels withstand much higher loadings than rubber tyred wheels. They are guaranteed to give at least ten times the working life, and to require far less tractive effort than conventional rubber tyred wheels.