Mr Evans, from Capel Dewi, Ceredigion, died aft the clang and 4 others were earnestly injured.
A further 11 radical sustained injuries which required infirmary treatment
On Tuesday, the RAIB issued an update connected the investigation, adding that an automated strategy that helps bid wheels grip tracks failed.
It said archetypal investigation indicated that the 1J25 work from Shrewsbury to Aberystwyth was travelling betwixt 15mph (24 km/h) and 24mph (39 km/h).
The 1S71service from Machynlleth to Shrewsbury was travelling astatine astir 6mph (10 km/h) successful the other direction.
The RAIB is continuing to analyse grounds relating to the collision speed, which it said remained an country of ongoing investigation.