In the Lincolnshire accident the collision did indeed happen on a curve in a cutting, so that the train driver had in effect no sight of the vehicle until he was right on top of it; he was apparently doing about 60 mph at the time and braked hard as soon as the obstruction was spotted, but obviously this was far too late to avoid a collision. Some passengers were thrown about in the accident and there were some 'walking wounded' who were taken to hospital for check-ups - ISTR that the worst injury was a badly strained shoulder, and everyone was released within a few hours. The train driver was unhurt but - naturally enough - deeply shocked.The vehicle driver, who was actually in his van and on his mobile to the emergency services at the instant the train arrived on the scene, was killed on the spot.
At Great Heck the circumstances were very different. Linespeed at this point is I think 125 mph, and the track is straight and well-suited for high-speed operation, but there were very unlucky factors which caused a number of fatalities.
The Landrover and trailer (with another vehicle being carried on the latter) had come to rest foul of gauge at the foot of the embankment. It was almost immediately struck by one of GNER's fast passenger trains which seems to have been running at linespeed or just below, and the vehicle was deflected from the line.
As the vehicle was in the lee of the motorway overbridge, it may well not have been very visible from the express cab, though I don't think that point was addressed in court - I suppose it is possible that the train was already braking at this point, though.
However, debris from the vehicle had apparently become caught under the train, causing at least one of the coach bogies (trucks to you!) to become derailed, though the train remained substantially in line and was being brought to a controlled emergency stop.
At this location some other tracks turn away from the main line, and the derailed wheels were caught by the pointwork, pulling the derailed coach further out of line, though not so far as would normally have caused serious problems - the couplers had apparently stood up to the strain and everything was still upright and more or less in line.
This is where the really bad luck happened. A heavy freight train was travelling in the opposite direction, and the locomotive of that train struck the side of the derailed coach; in that impact one of the men on the freight train's locomotive was killed, together with some of the passengers in the derailed coach.
Bearing in mind that the impact between the two trains was probably at a combined speed of around 175 mph or thereabouts, and that the passenger coach was struck in the side by a heavy freight train, the death toll was low - under double figures I think, though someone may correct that here.
So the Great Heck crash wasn't a simple 'train hits vehicle' incident, as you may have assumed, but rather a tragic combination of circumstances. Oddly and coincidentally, Gary Hart - the driver now in jail for the manslauhter of those killed - was also on his mobile to the emergency services at the time of the crash, and the dramatic tape of the call was heard at his trial, as he shouts 'There's a train coming', followed almost immediately by the sound of a massive impact. If nothing else had happened, however - in particular if there had been no train coming the other way - probably everyone would have walked away with nothing worse than a few bruises.
John