Drapes, It had been thought of before, and this bit does surprise me. The Manchester, from which Roy Chadwick developed the Lancaster, had a beefed up structure designed for catapult launch! Words below from ‘Lancaster at War 2’ – Garbett & Goulding.
‘Two factors in the original Manchester specification and design provided the (political) “escape route” which led directly to the Lancaster Mk I. Air Ministry specification P13/36 had called for an airframe structure capable of sustaining the loads arising from catapult launching, amongst which was the high inertia drag loading in the wing structure. This load had been taken care of by using relatively thick skin plating. By the time Chadwick pressed ahead with his four-engined Manchester, catapult launching was no longer a requirement. Increased wing span on the other hand was now an obvious necessity, and could readily be obtained simply and at little tooling cost or delay in production. One simply “stretched” the original wing. All existing wing ribs were retained, pitched, however some three inches further apart. The spars were stretched to suit by extruding longer booms, which could be machined on the existing Avro designed milling machines, the base of which could easily be adapted to suit. The limiting factor was the ability of the extrusion press at High Duty Alloys to work continuously at maximum capacity without breakdown until a bigger press could be built. I have recollections of a very heated high level meeting at Chadderton where Avro, High Duty Alloys, Air Ministry and Ministry of Aircraft Production representatives hammered out the risks and benefits involved. Fortunately Avro and HDA were given permission to proceed. With no catapult load requirement it was possible to use thinner skin throughout the end product was a wing of 102ft span, lighter and stronger.