The Belvedere was coming along well until the Royal Navy got their hands on it. It was they that insisted on a mantis like front undercarriage so as to fulfil a half mad requirement to carry a torpedo. Having totally fouled up the design they then cancelled it.
The RAF had to take it on with the funny undercarriage as opposed to the original level design which preceded the Chinook's. The original project had piston engines so converting to gas turbines with the inlets in the ideal vacuum cleaner position was not a good idea, but again it was supposed to operate off continually washed carrier decks.
Bristol already had the design ready for conversion with two gas turbines mounted aft at the base of the rear rotor mast much like the Chinook but Wastelands took over the design and production so the RAF was saddled with what was going.
It could fly on one engine but a unique advantage was that it would fly with the transfer shaft, (the shaft along the back that kept the rotors in sync and enabled one engine to drive both rotors), broken as the main rotor planes were far enough apart so that the blades did not collide in normal flight.
When it was working well it could lug most things that needed lugging about. When they finally wrapped up 66 Sqn in Singapore I am told that when they wheeled out the war reserve Belvedere from the Maintenance Unit in Seletar it was found to have the same serial number as one of the squadron's aircraft.