I haven't read the article and am not going to waste one penny on buying TRAINS these days. But if the gist of this thread is correct then this is a major change for the folks at TRAINS regarding their long time view of the validity of the 8 mile Cascade Tunnel. The long standing view was that the new Cascade Tunnel was the greatest thing to happen to the GN, possibly saving the company from bankruptcy during the Great Depression. Yet various railroad analysts have pointed out that the cost of the tunnel construction hadn't really been recouped over the years, and once it was decided to dieselize the line it lost it's profile advantage due to the need to clear out fumes for subsequent trains.

I think the unstated hypothesis is correct, in that if the old line was still up and running today that particular line might be more fluid than it is with the new tunnel. Although the eastbound grades in the tunnels are identical (and of course the old line is about 10 miles longer), obviously the shorter length of the old tunnel would take exponentially less time to clear of diesel fumes assuming identical ventilation systems. Rebuilding/reinforcing the old line's showsheds may have been a lower cost option in the long run. Of course at the time the GN had no indication of the upcoming diesel revolution, and their thoughts were that either line would be electric operation for the foreseeable future.

Personally I think with today's technology the best idea for increasing capacity of the Stevens Pass line would be to install a third rail inside the tunnel and use either remote control electric DPU's, or equip all the diesel's predicated to that line with pick-up shoes.