CME Newsletter, No. 42, April 1987

As part of a major project to upgrade the Fraser Valley portion of the Trans Canada (Hwy 1) to true freeway standards, a secondary crossing of the Vedder Canal was needed. This service route would eliminate slow-moving farm traffic from Hwy 1 and would permit the closing of some uncontrolled access points. Keith Wilson Road, which bisects CFB Chilliwack, was chosen. It would be extended across the Vedder Canal some 8.5 km west of the Base. Acrow panel bridge, supported on six piers, was selected to span the gap.

Note – Acrow panel is the modern successor to Bailey. For a 6.7% increase in panel weight and up-dated methods for connecting transoms and sway bracing, shear and bending moment capacities are greatly increased. This and other technical aspects of Acrow, as well as engineering lessons learned in the erection of this bridge, will be discussed in a separate article.

The fortunate location of the B.C. Acrow representatives down the hall for our own Colonel Commandant’s Vancouver office served to form the “bridge” between the B.C. Ministry of Transport and Canadian Military Engineers. While approval was being sought from NDHQ for 1 CER participation, civilian contractors emplaced the abutments and the concrete-capped tubular steel piles (concrete filled) to form the piers. MOT built the access route and prepared the approaches.

Shortly after project approval was received, some 80 members of 1 CER, in less than twelve working hours, erected two hundred tonnes of steel over the 600 foot gap. Here is an account of the task as written by WO Scotty Nicholson, 1 Tp WO, who looked after PR and recording the event:

In peacetime we, the Engineers, are rarely given the opportunity to demonstrate our engineering skills and professionalism to the public. 1 CER was fortunate enough to get such an opportunity during the period 25 – 28 Nov 86 by constructing a 600 ft/183 m seven span Acrow bridge over the Vedder Canal. The Acrow is a civilian bridge similar to the Bailey. The Acrow retains many of the basic Bailey principles incorporating some strengthening features of the heavy guider bridge. The Acrow is capable of supporting MLC 60 over a 200 ft/61 m clear span using a normal configuration, Quadruple Double Reinforced (QDR), and is normally constructed by hand.

At 0800 hrs on the 25 Nov 86, MWO Dave Fowler (Bridge Commander) gave the order to prepare the site for construction during which time the roller layout was progressing and small stores were being unloaded.

At 1215, MWO Fowler gave the order, “panels up,” which initiated a beehive of activity. Normal construction continued up to 1630 hrs with the nose touching down on pier #1 at 1500 hrs. Prior to the bridge reaching Pier #2, rumblings could be heard, “it will never line up on the rollers on pier #2”. As the bridge inched forward, all held their breath as the nose touched down exactly as planned, perfectly aligned, a job well done by Sgt Mears and his roller layout crew. And so day one came to a close.

Day 2 construction started at 0800 hrs with MWO Fowler giving the all familiar order “panels up”. Normal construction continued throughout the day and reasonably smoothly. The nose touched down on the piers at the following times:

Pier # 3          0900 hrs

Pier # 4         1040 hrs

Pier # 5         1340 hrs

Pier # 6         1430 hrs

Far landing Rollers                       1517 hrs

Jacked down home side           1601 hrs

Nose dismantled                          1610 hrs

A few days of anxiety did come when the bridge reached Pier # 4 and it started to react like a snake. The panel metal appeared to compress and as the tension/compression released, a wave like action passed throughout its length. This was an unfamiliar occurrence which was later confirmed to be a normal reaction of long bridges as they are being pushed forward. Once the bridge proper reached the far side, the home side was jacked down and the nose removed. Work for day 2 came to a close and all members left with a feeling of a job well done.

During the 27 and 28 Nov, MWO Fowler, with a skeleton crew, jacked the bridge down and cleaned up the site.

The actual construction time was equal to 9.5 hrs to span the canal and have the home side jacked down. A considerable feat considering the length and number of spans.

During the construction, civilian spectators were heard to say: “Unbelievable, why did we not get the Army engineers to put a bridge in years prior?” all comments were of a positive nature, 1 CER earning the respect of the local populace.

Although the Acrow bridge construction occupied elements of the unit for the better part of a week, it was a truly satisfying project. The bridge has opened up a much needed secondary route across the Vedder Canal and will remain in use for years to come. Members of three squadrons, and even RHQ, were heavily involved in all aspects of the construction. It was the type of project that is rarely available and, as the sappers will agree, was very rewarding.

Is this the longest Bailey-type bridge built by Military Engineers in Canada? Vince Clark remembers building 600 feet of Bailey over the Peace in the 1950’s; however Acrow end panels are somewhat wider than Bailey which would give the 1 CER bridge over the Vedder Canal some eight inches more than that built by our predecessors’.

Footnote – this bridge was replaced in 1998, with it’s opening taking place in Dec 98. This time construction was by civilian contract.

Note to cross the Vedder River/Canal, there are only three places this can be done. The two bridges (two lanes each) side by side, on the Trans-Canada Highway. The Keith Wilson bridge and finally the bridge in Vedder Crossing. This third bridge will be replace over the next couple of years.

Bridge co-ordinates – 49°6’10″N   122°4’39″W