Rivers / Daly Heritage / Interpretive Signs
Sign #5: The Trestle Bridge


The Rivers Trestle (Photo from the Rivers Library Collection)

Railway builders loved the prairies.

Most experienced builders and contractors that came to these plains had experience with the mountains, hills and rolling country of the eastern part of the continent. Some had experienced the challenges provided by the rocky outcrops of the Canadian Shield.

We had the technology to tunnel through mountains, to cross wide deep valleys, and wind a path through, rather than over, hills and other obstructions.

What a railway needs is flatness. A train hates a steep grade, in fact a rise of even 2 metres for every hundred travelled ( a 2% grade) is considered unacceptable. The whole efficiency of the locomotive is lost if you have to provide enough power to just step on the accelerator like you would in a car to get over the hill. For the builder, negotiating hills and valleys in such a way that we keep the trains on a low grade add great cost to the process of railway building. That’s why if you look a map you will notice that a rail line is sometimes diverted several miles to avoid the expense of going over a hill.

So when the earliest railway builders arrived on the prairies, say, at Winnipeg, and started travelling west, over those flat plains towards Portage, they must have been quite happy.

But they did have the survey reports, and knew that there were a few challenges ahead.

The job of the surveyor is to select the path of least resistance for the tracks. A walk or bike ride along an abandoned rail line brings this to life. The trail will twist and turn to avoid hills and valleys. The job of the railway construction crew is to take that path of least resistance and work with it.

That means it’s a process of levelling using what came to be known as cuts and fills.
For small elevations you cut a path through so that the tracks run through an excavated section lower than the surround ground level. For modest depressions you build up the grade (sometimes using “fill” from the last “cut”).

If the depression involves any sort of waterway you need to allow that water to pass. Small seasonal streams may require only a culvert, larger ones, a bridge.

And that will get you across quite a bit of the prairies.

Finding the “Best Crossing”

Old carpenters will tell you to measure twice and cut once. That wisdom applies manifold to the railway construction business. The measuring is done by a survey.

Long before construction started on Canada’s first Trans-Continental Railway there was extensive surveying in Western Canada. Of course the Rocky Mountain presented the biggest barrier, but one couldn’t afford to make mistakes on the prairies either.
The plains were mapped in a general way quite accurately by the Palliser and Hind expeditions in from 1857 – 1860. We knew where the rivers where and quite a bit about elevation, drainage and climate conditions. As early as 1873, formal surveys started plotting possible routes. Many options were presented. Geographic considerations were balanced with political and business considerations and a main route was chosen. Construction started in 1880 and was completed to the coast in 1885.

Nearly twenty years later the Grand Trunk Pacific was planning its competing line. From a business point of view it needed to fill a void not well served by current lines, so its ideal route was generally determined. Local decisions about crossing were also easier to make because of all the surveys already done. 

Everyone involved knew exactly what the main challenges were. The first was at the Pine Creek crossing near the hamlet of Firdale, and the second was the crossing of the Little Saskatchewan near the village of Wheatland.

When there is a river to be crossed, a surveyor looks for the place that it can be most efficiently bridged - the best crossing. The search for such best crossings has determined the location of many a town and city as the railways crossed our land.

Designing the Crossing

When faced with a river crossing even after the site is determined there is still an important decision to make.

The Little Saskatchewan is a little river in a big valley, a valley left over from the huge streams that drained the meltwater from the last ice age. There are two accepted ways to cross a deep valley. One is to plot a gentle decline along the edge of the valley, cross the river on modest bridge, then plot an equally gentle climb up the other side. This can take one on quite a detour, and that in itself can be expensive.

Or one can cross at the top by building a bridge from rim to rim of the valley, far above the stream.

The Little Saskatchewan had already been crossed once in this area, by the C.P.R. that extended a branch from Brandon to Lenore, by way of Wheatland and Bradwardine.
A look at the following photos of the C.P.R. Bridge at Cossar Crossing and the current C.N. Bridge near rivers show the difference in height.  The map and Google Earth image shows how the C.P.R used method 1. They twisted and turned to find a low crossing. While the Grand Trunk who originally built the Rivers Trestle in 1908, used a more direct route and a high bridge.

Both companies selected virtually the same ”good crossing” – less than a kilometre apart.


 Cossar Crossing. Photo courtesy the McKee Archives, Brandon University

River Trestle Bridge. Photo courtesy Archives of Manitoba


The Rivers region in 1915.

Grant’s Cut

Because the contractor chose to build on a fairly direct route spanning the whole valley some excavation was requited in the hills south of the trestle to level the rail line. The dirt removed to make the cut was used to fill in the original trestle, creating a stronger structure and decreasing the fire hazard. A ravine was cut with a steam shovel to divert water run-off so the new fill was not washed away. The result to this day is known as Grant’s Cut likely named after the Resident Engineer in charge of construction along that stretch of line.

The beginning of Grant’s Cut

Google Earth image showing the CP and Grand Trunk lines approaching crossing of the Little Saskatchewan River.

Laying the Foundation

The first trestle was built of wood. A slightly longer and higher bridge built a year later at Duhamel, took over 6 million board feet of Douglas Fir, with about one third of that going into the piles alone.

Those piles, that end up supporting the full weight of the structure and the trains that cross it were sunk deep into the ground. A visible reminder is available at the site of the Pine Creek crossing.  The original trestle, was replaced by a “big fill” when the bridge was barely a decade old. The following photos show the site today.


The newly built Pine Creek trestle (Photo from the Archives of Manitoba)


The replacement fill is to the left while the old Pine Creek trestle was near the centre of this photo.

Building the Structure

The engineering principals and construction procedures were tried and true by 1900.
The Grand Trunk Pacific chose a C.P.R. veteran Horace Haney to supervise the building of trestles in the west. Haney had extensive experience in trestle bridge construction for the C.P.R., including work in the Rocky Mountains.


Horace Haney and his Granddaughter, Edith Bonner


Horace Haney (second from the right) and his work crew at Battle River (Duhamel Bridge).
From the collection of W.J. Bonner, Miniota Mb. And donated by his son, John Horace Bonner

Working from an appropriately wide base, and supported by the aforementioned piles, a series wooden beams called bents, are connected by horizontal beams, walers and crossbracing,  are fastened with bolts to create a framework upon which a deck is set and tracks are laid. The format used can be seen in all the photos of western trestles, the variables being length and height.


Wood Trestle Bridge Construction. From the collection of W.J. Bonner, Miniota Mb. And donated by his son, John Horace Bonner

Along with the massive initial investment, the Rivers bridge, like most railway bridges, required considerable ongoing maintenance and upgrades.

In some cases, such as at Battle River (Duhamel Bridge), a crossing was abandoned and a track re-routed to a neighbouring track (In that case the CNR line was nearby,) In other cases such as Pine Creek a fill replaced the trestle.

In Rivers, period improvements were made over a long span of time beginning almost immediately.

The filling of the trestle started almost as soon as the trestle was completed. This was standard practice as the fill stabilized the whole structure. The temporary bents on either approach would have been filled as soon as possible. As seen on the big image of the trestle (taken pre-1910—the locomotive #507 was renumbered #807 in 1910), the filling has already started at both ends of the permanent structure.

The bulk of the filling occurred between 1921 and 1922. As one CNR report, dated 27 August 1921, stated. "Fair progress is being made on this work (Tilling). We are averaging about 1800 cubic yards per day."

The main filling was done over the course of two seasons. Cars were loaded with fill by steam shovel at Grant's cut. A locomotive hauled the loaded cars to the bridge site where they were emptied along either side and both ends of the bridge. As the height of the embankment increased, the horizontal elements of the bridge (walers and crossbracing) were removed. Once the embankment reached the level of the deck at the top of the bridge, the fill was allowed to settle for one season. The next year the filling was completed and the deck was removed.


Loading material taken from a fill. From the collection of W.J. Bonner, Miniota Mb. And donated by his son, John Horace Bonner

So, if you dug into the embankment today you would find the vertical parts of the bridge (the bents), exactly as they were when the filling started! Even though the timbers were untreated, they should be quite well preserved as they have not been exposed to the air.

The Steel Structure

In 1924, a portion of the unfilled trestle over the roadway diversion and the river was replaced with a short piece of steel bridging. The steel was fabricated and erected by the Dominion Bridge Company.

In the following years there were ongoing problems with the earth embankment, nothing unusual for such a large fill. In the early 1930s, it was noted that the embankment was shoving too hard on the end bents of the timber approaches, and it was considered necessary to extend the bridge. In 1937, one bent was added to the west approach and two bents were added to the east approach.

Over the years, the timber approaches were replaced. Finally in 1970, the timber approaches were replaced with steel. Steel spans and towers similar to what had been installed in 1924, were installed at both ends of the existing steel bridge, bringing the bridge to the appearance we are familiar with today.


The Rivers Trestle Bride, serving today after many modifications over the years.