Being drunk is not an excuse for posting such vitriol.
Some knowledge of physics and mechanical engineering would normally be considered good form if one is trying to make comments on the outcomes of accidents or the safety of particular designs of rolling stock.
Firstly, the HST cab might be only a ‘fibreglass tub’ but it is a very strong fibreglass tub. Since introduction on 1976 there have only been, by my count, three accidents where the train drivers have been killed. These are Ladbroke Grove, Ufton Nervet and now Carmont. In all three cases these were high speed incidents so the energies involved were considerable. It should also be noted that the causes of all three accidents and their development were very different in all cases.
At lower speeds the HST’s cab design affords protection to the levels expected when the train was designed in the late 1960s. For example at Newton Abbot in 1994 a 158 collided with the rear of a stationary HST which crumpled some fibreglass below the HST’s windscreen but bent the 158’s body sufficiently that the front doors jammed, see this Youtube video:
Similarly the nose of an HST left its mark on the front of a 150 which ran into it:
In March 2013 an HST struck a car on the level crossing at Athelney at around 100mph. The car driver was killed but the train did not derail and came to a stand about a mile further on. No passengers or crew were injured; a very different outcome to the almost identical crash at Ufton Nervet or the events at Carmont
So, maybe a ‘fibreglass tub’ but a very strong one.
Equally there are clearly some weak points, at Lavington a fallen tree broke the near side pillar around the windscreen as the HST hit it at speed. Luckily the driver ducked in time but the resulting pictures were dramatic.
The point about all this is, as others have pointed out already, a design does not become ‘unsafe’ overnight simply because an accident has occurred. Design standards have evolved over the years from the ability to withstand compressive loads at buffer and coupler level, common up to the 1950s, to improvements in ‘anti-telescoping’ features in the 1950s for coaching stock, firstly in the BR Mark 1 coach and more comprehensively in the monocoque Mark 2. All this stock has co-existed, later stock has not replaced the earlier in one fell swoop.
By the 1980s British Rail began to investigate the incorporation of ‘crumple zones’ at the ends of passenger vehicles to absorb energy in ‘head on’ impacts and led to the demonstration that the capability of vehicles to absorb one megajoule of energy would help to ameliorate the effect of collisions at speeds up to 40 mph. Since then designs have been evolved which can absorb 5-10 megajoules.
It should be made clear that the energies involved in high speed head on collisions are enormous. At a constant velocity kinetic energy increases linearly with train mass but the kinetic energy increases as the
square of its velocity so at high speeds the values are enormous. Very approximately, a 40 tonne rail vehicle moving at 25kph (say 16mph) has a kinetic energy of nearly 1 megajoule, at 100kph (62mph) it's just over 15 megajoules and at 200kph it's 62 megajoules. A ten coach train travelling at 200kph will therefore contain some 620 megajoules of energy. This is more than
sixty times that which can be absorbed in one crumple zone at the front of the train.
It is an unfortunate but unavoidable fact that this level of energy cannot be dissipated in the length and dimensions of the space available in front of the driver if the deceleration levels are to be kept tolerable. At best, protection for the driver can be provided for impacts into immoveable objects at moderate speeds and this is specified for new rail vehicle designs in British Standard BS EN 15227:2008 and amendments. In its preamble it is stated that the requirements are to provide a level of protection by addressing the most common types of collision that cause injuries and fatalities, they do not cover all possible accident scenarios but provide a level of crashworthiness that will reduce the consequences of an accident, when the active safety measures have been inadequate. The crashworthiness specifications are intended to enhance the safety of passengers and train crew, in the event of a collision. Thus the theoretical survival area, for example part of the driving compartment, must remain intact following a collision. Collision scenarios are given in Clause 5:
- a head-on collision between two identical train formations;
- a head-on collision between the train and a different type of rail-mounted vehicle;
- a collision between the train and a large road vehicle on a level crossing;
- a collision between the train and a smaller obstacle, such as a car on a level crossing, an animal or debris.
Three impact zones are defined: an upper level above the buffer/drawgear, a main level at the buffer/drawgear height and a lower level which tests the obstacle deflector.
The large road vehicle is modelled as a 15 tonne mass on a stand and BS EN 15227 requires that railway vehicles need to be able to absorb the energy of a crash that occurs at speeds up to 36 km/h, in old money that’s 22.37 mph. Given the mass of railway vehicles, this requirement equates to a need to absorb approximately 20 times more energy than a typical car crash.
In the 46 years since introduction, and heaven knows how many tens of millions of miles travelled, for the HSTs to have had only three driver fatalities is a remarkable achievement. This is not to say that the three fatalities were not tragedies which affected and continue to effect, the lives of the families and colleagues of those killed; it is simply to point out that such events are, thankfully, very, very rare.
Added in edit: If the DfT had not muddied the waters at the time when at least two TOCs were feeling their way to an 'HST2' and subsumed them into the Intercity Express Programme then newer and more robust cab designs may well have entered service a dozen years ago
