Model collapsible structure : Sergeant A Worsfold, AIF Research Section, Imber Court Experimental Grounds

Model of an oval framework structure which can expand and contract with a scissor-arm concertina action. Model consists of six ovaloid copper forms, each with a large central rectangular cut-out, and each flat at one end. Mounted vertically within each cut-out, and wired into place, is an alloy stringer. Its centre forms the mounting point for the wooden scissor arms which allow the model to expand and contract. These arms are reinforced with glued cotton tape and pivot on copper wire pins. A loop of string also runs centrally within the arms, restricting expansion to a certain point. A loop of black leather thonging is strung through the upper and lower outer circumference of each copper oval, tied at each end, and perform the same function as the string. Extra steel wire attached to each oval form provides strength and reinforcement to both the forms and the action.

This model illustrates one of the many inventions of 12096 Private Alexander Worsfold, 9th Australian Field Ambulance.