Re: "Romance of the rails" still lives on (Oct. 15):

Both VIA Rail Canada and SNC Lavalin (who will build and operate the Pearson Airport Link) would love to use new, modern Diesel Multiple Units (DMUs, but there are a number of problems.

Most of these trains would run on CN lines and CN have a System Standard regarding light trains, in that a single vehicle is limited to 30 m.p.h. and a two-vehicle train is limited to 50 m.p.h., hardly speeds that would entice people away from their cars. The reasoning is that light trains do not necessarily shunt the rails properly and might not activate the signal systems and crossing warning systems. More about this later.

The other issue is the standards to which rail cars are built. The U.S. standard, as mandated by the Federal Railway Authority (FRA), specifies a very heavy and robust vehicle, most likely because in the past passenger cars could be included in the consist of a freight train and would have to withstand those stresses. There is also a 'crashability' issue if the vehicle was to hit another train.

Currently no manufacturer makes a passenger vehicle to these standards. Colorado Railcar was attempting to but has gone bankrupt — their assets have been bought by US Railcar who hope to revive this effort.

You mention the old RDC or Budd Cars that used to run on many lines in Ontario (and do meet the FRA Specs) — there are approximately 50 of these vehicles left in North America in various states of repair. Since they do have stainless steel frames they can be retrofitted with new engines (Tier IV?) and put into service even though they are over 50 years old and weigh about 70 tonnes.

Railways can run lighter vehicles but not where there is mixed freight and passenger service. For example, the O-Train in Ottawa which runs Bombardier Talent DMUs, but only allows freight traffic on the line at night when passenger service is not running.

In Europe, on the other hand, DMUs have become a standard for most back line operations. These new DMUs are made by all major manufacturers (Alstom, Bombardier and Siemens) and the new designs weigh about one half the weight of an old Budd Car (about 30 tonnes). They can operate at speeds up to 90 m.p.h. and would be a great addition to VIA's fleet. To ensure proper operation of the signal systems, all DMUs, in the U.K. and Ireland, are equipped with Track Circuit Assistors (TCAs) which induce an electrical current between the wheels and rail to enhance electrical shunting. As regards crash standards, the DMUs are designed to deform in an accident and roll to the side away from the opposing obstruction and numerous tests have concluded that passenger safety is probably increased with this feature.

Applications have been made to Transport Canada for an exemption to allow European DMUs to run on freight lines in Canada, but to my knowledge this exemption has not been granted.

Another option would be to install TCAs on rebuilt Budd Cars and have CN allow higher speeds on their lines.

Hopefully in the near future passenger service can returned to some of these smaller cities using new technologies that are available elsewhere in the world.

Bill Mountain

Orangeville