The only thing that is not particularly similar with the above front tipping dram,is that it does not appear to have buffers and a hitchin plate.
Several types of drams were used in the Welsh Coal Mines,squared sided as shown,Vee`s and similar shaped to Tredomen`s except they had chassis and frame work.
The majority of drams in the big Collieries went through chamber tippers,hence Hudson and Tredomen were the big players,
The majority of the Smallmines,in-fact all that i worked in used front tippers of varying shapes,even home made bodies on the old chassis,one Colliery the Helig in Cwmllynfell had front tippers,but the doors opened side ways,the only ones i ever seen.