Dragbox Manufacture in Progress

Dragbox manufacture is in progress at TCL Seal of Sheffield.  The profile cut plates are shown to the left. They are heavier than they look, probably about ¾ ton or more. On the lower right is the welded-up “H” section on its side. This takes the pivot pin for the drawbar and transmits the load to the rest of the dragbox and then into the frame plates. It will now be drilled for the pivot pin and for bolts in each side plate to secure the large Vee bracket that supports the brake linkage bell crank.

Once that intermediate machining stage is complete the dragbox will be welded up.  Due to the heavy sections and large welds, there is a risk of shrinkage forces distorting the welded assembly.  Heating the assembly in a controlled furnace (“stress relieving”) will control this.

Final machining will skim the two sides of the assembly and 30 bolt holes will be drilled in each side to complete the manufacture.