Tripcocks are only used on the Underground so there is no requirement for them on these reborn trains!
Haven't you missed the point? AIUI, lower crashworthiness standards are permitted on tripcock-fitted lines (including lines where where LU and NR trains currently co-exist) because the likelihood of collisions is deemed to be so low. Crashworthiness should therefore require upgrading if the D78s are intended to be used on non-tripcock lines. It should also be noted that although the D78s will not have their maximum speed increased, they will potentially find themselves on lines where other trains are permitted to go nearly twice as fast as they can, which will also make crashworthiness more important.
The issue is more than Tripcocks as you you have now clarified, however I think I would feel happier and safer in a former D78 rather than a Pacer held together by lots of rivets any day! As has been stated already Adrian Shooter is a smart cookie and I am sure he has already covered this issue.
Everyone seems to have forgotten that there's still a lot of heritage stock allowed on the main lines at up to 100mph that probably doesn't meet modern crashworthiness standards. I'd suggest there's "grandfather rights" for certain stock (VSOE Pullmans, Mk1 charter trains...) and that LU stock will come into that category.
They have been performing low speed crash tests on 7056 which has had the crash structure modifications. I suspect that this is more of a validation for computer simulations rather than a crash test in the more conventional sense. From the looks of it, the reinforcement has been riveting some plate to the underside of the windows and over the M door, as well as what appears to be some internal reinforcement running above the nearside/offside doors, a beam across and triangulation posts running down the side of the M door.
They have been performing low speed crash tests on 7056 which has had the crash structure modifications.
The mods look very much less significant than the "Darth Vader"- style cladding shown in the artist's impression. I would assume from the damage sustained by 7056 in protecting its dummy occupant that it is to be written off, or is there enough of it undamaged to make an intermediate car?
Looks like it came out of that with pretty light damage!
Look at the in-cab picture - there's quite a lot of distortion. This is I assume intentional, to act as a crumple zone and protect the driver (whose position has been moved back relative to the LU driving position)
The higher standards of crashworthiness required on NR are presumably because on lines not fitted with trip cocks there is more risk of a collision, and some of the lines they might work have higher speed limits than LU experience. (The D trains won't be cleared for 100mph plus, but they might encounter trains which are).
There is also a far greater range of things they could potentially hit on NR than on LU, as the former has level crossings. Indeed I think the test was designed to simulate hitting a farm tractor - something that a train running entirely in urban and suburban London is very unlikely ever to encounter.
The essential things in life are seen not with the eyes, but with the heart. --Antoine de St. Exupery