by Eleanor Deckert
Part two of a series celebrating 100 years of railroading in the North Thompson valley, 1915 – 2015.
What does a surveyor do?
A composer experiences an inner soundscape. Using an agreed upon notation system he can capture his creative experience onto two-dimensional paper. Later, others who understand the notations can read and orchestrate the sound-experience so that an audience can enter the world the composer discovered.
A surveyor experiences an external landscape. Using an agreed upon notation system he can capture his three-dimensional experience onto two-dimensional paper. Later, others who understand the notations can read, orchestrate decisions, plan and build transportation links so that passengers can enter the world that the surveyor discovered.
From ancient times, the surveyor’s skills have brought civilizations forward. To walk into uncharted territory with the intention of planning a railroad bed through the Canadian mountain chains required surveyor crews with an exceptionally large dose of endurance.
From north to south the mountain passes are: Dease Lake, Pine, McGregor, Robson, Yellowhead, Athabasca, Howse, Kicking Horse, Vermillion, Simpson and Crowsnest Pass.
Sandford Fleming (responsible for proposing standardized 24-hour times zones) oversaw the surveyor’s maps begun in 1871* and favoured the route through the Yellowhead Pass, although others decided to build Canada’s first transcontinental railway (Canadian Pacific) through Kicking Horse Pass.
*”The numbers are staggering: 800 men in 21 divisions toiled, suffered and surveyed 46,000 miles of line of which 11,500 miles were laboriously measured.”railways.library.ualberta.ca
During the decades of the late 1800s, several competing railroad companies jockeyed for position juggling the pros and cons of alternative routes, seeking pledges of finances, clarifying legal matters and negotiating with various levels of government.
William Mackenzie and Donald Mann, familiar with railroad building, formed the Canadian Northern Railway in 1901. The Yellowhead Pass was chosen because it offered the least change in elevation. Surveyors were sent into the North Thompson valley in 1909 and were successful in finding a route the sea. This railroad project was finished in 1915.
River valleys are to the surveyor’s advantage. This natural pathway it is known to run towards the final destination: the sea port.
River valleys are also a surveyor’s nightmare with various obstacles, dangers and challenges. Complex measurements have to be taken. Marshlands are unacceptable roadbed. Hazards mean money.
Over a distance of 100 feet, how many feet does the roadbed rise? This measurement is called “the grade” and is of primary concern. No more than two per cent grade is the ideal. More than this and the increased fuel costs needed to move the weight rapidly multiplies.
To achieve this barely perceptible grade, tunnels and switchbacks, trestles and fill, river crossings and bridges are necessary expenses in the beginning to save on-going expenses later.
Besides the axe, all of the normal travelling gear and supplies for a lengthy overland crew, the three main tools of the surveyor are: rod, chain and theodolite.
The rod was 11 feet long with painted measurement units marked, made of well-seasoned yellow pine which had been immersed in boiling paraffin to prevent variations.
The chain, 66 feet long made of 100 links, must be held with the same tension when each measurement was taken.
The theodolite was an instrument on the bearing table on the top of the surveyor’s tripod which was a composite of: a compass (orient to magnetic north), bubble-level (horizontal level), plumb-bob (straight down to reference point), cross-hair site (view the markings on the rod), azimuth scale (horizontal degrees), elevation scale (vertical degrees).
Accuracy is the point. Errors can include: the difference between magnetic north and true north and how longitude changes when latitude changes, any damage to any of the instruments, changes in temperature and humidity, tension of the chain, even the handwriting of the record keeper can bring misunderstandings and errors.
Complex calculations are involved when surveying barriers and routes around them. Are records made at the time measurements are taken, or from memory at the end of the day? Any time there is a suspicion of error, the survey crew must repeat measurements, beginning with whatever previous reference point was certain.
Constant and variable
The present reference point is a constant. The uncharted point up ahead is a variable. But, each time a step forward is taken, exploring into the unknown, carrying equipment through the mud and mire, as the measurements are taken and recorded, the new point becomes a mathematically known legal point that can only exist in one place. And so on and so on until the transcontinental roadbed can be plotted.
Edmonton to Vancouver
It’s just over 600 miles. In 2015, we are so accustomed to zipping along, checking the GPS, listening to music, comfy seats, air conditioner or heater adjusted to our liking.
It’s hard to comprehend the contrast with travel conditions before 1915, and be grateful for the surveyors who made it through the first time: boots and axe, rod and plumb-line, paper and pencil, the complex transit and a simplicity of the 66-foot long chain.
We don’t know their names. We don’t know their story. But we do travel along their path.