Between 1925 and 1932 C.N. operated over 100 special silk trains across Canada. These trains had priority over all rail traffic, including passenger service.
In July 1925, the first silk train special left the Port of Vancouver containing eight sealed baggage cars lined with a special paper to protect the shipment from dampness and dust. It was guarded by two armed C.N. Police. The cargo was worth approximately two million dollars.
In October 1927, the biggest C.N. silk train left the Port of Vancouver enroute to the National Silk Exchange in New York. The train consisted of some 21 express cars in two sections and contained 7,200 bales of silk worth seven million dollars. It took an estimated two billion worms to make that much silk. Raw silk was not subject to duty fees by the U.S. so the trains could cross the border without delay.
An intriguing story circulated that in each bale of silk were living silk worms, spinning their hearts out as the silk train sped across Canada on the way to New York. The story was false, of course; there was nothing in the bales but raw silk. The secret of making silk lies in knowing exactly when to kill the caterpillar while it is still in the worm (chrysalis) stage. If left too late, the emerging moth or butterfly could ruin the cocoon; if done too soon, the silk would not be ready for market.
The "Silker", as it was known, was not operated by any special crew, but by the crew that happened to be "next up" on the board. The locomotives used were fast locomotives that had been designed for high speeds in passenger service. Despite speeds of up to 90 miles an hour, there were few recorded accidents.
Silk trains in the west left Vancouver, and locomotives were changed at Boston Bar, British Columbia (BC); Kamloops, BC; Jasper, Alberta; and then Edmonton. This procedure was repeated at each terminal on the Canadian National system until the train reached its destination. It took approximately four to seven minutes to service these trains and put on another locomotive at each divisional point.