Planning Rural Roads

Mechanization of construction

First tracked vehicule

First self-propelled vehicle ever photographed (1857)

The US was the prime mover in labor-saving innovations, first in agriculture and then in construction. An animal-drawn scraper was actually invented in 1805 for agricultural purposes. However the mechanical reaper, developed in the 1840's and precursor, via the ingenious reaper and binder of 1871(try building a mechanism to tie a knot in a piece of string!), of the lumbering self-propelled combine-harvester of today, was one of the greatest agricultural innovations ever. It replaced the highly labour-intensive sickles and scythes of the time, increasing productivity by many orders of magnitude and enabled the extensive cultivation of the Canadian and American prairies despite the chronic scarcity of labour.

As it should, heavy, dangerous and dirty construction work has always commanded high wages on both continents. Although the navvies (mainly Irish construction workers) of the 19th century earned more or less average wages for the time of about 15 pence per day (about 9 GBP or 14 USD in today's purchasing power) they often succeeded in negotiating premiums of 50% or more for especially heavy or dirty work when they had the bargaining power to do so. They were highly productive when they worked, but, less docile than contemporary machinery, let off their excess steam in drinking bouts and recovering from them. Nevertheless, labour-intensive works were still favoured among contractors in the UK late in the century, assisted only by steam shovels and temporary steam railways. In North America, on the other hand, wage levels were significantly higher (about 1,35 USD per day at the turn of the century or about 20 USD in present day purchasing power), due to difficulties in recruiting large labor forces. They were also increasing rapidly, standing at two dollars per day in 1910 and four dollars ten years later. In all, during this century they have increased sevenfold in real terms to present North American levels of about twenty dollars to thirty dollars per hour.

The history of improvement in machine design, which took place mainly in the United States, provides a fascinating illustration of the principle of form following function. The specialization of earthmoving equipment, essentially as a function of haulage distance, giving rise to the grader, scraper, bulldozer, compactor, loader and the ubiquitous farm tractor , took place more or less between the 1880's and the end of the First World War. By this time they had all more or less adopted their familiar outlines. The elegant and purposeful design of the farm tractor has in fact changed little over nearly ninety years. Early graders, scrapers and compactors were animal-drawn, but the tractive effort necessary required teams of an inordinate size (teams of up to sixteen mules are mentioned) so it was not long before the tractor, and then the tracklayer were adapted to pull them. Soon they became self-propelled. The addition of the bulldozer blade to the crawler tractor, a key innovation for moving earth over short distances, came a bit later. The internal combustion engine was adopted quite early on, since steam traction did not dominate as in the UK, (fuelled by cheap coal), where its indestructibility (Victorian steam-engines often remained in service for a half-century or more) was undoubtedly a brake on the development of relatively light and agile machinery. Undoubtedly, its compactness and convenience greatly stimulated design. Although it was no trivial task to start an oil engine in freezing temperatures at the turn of the century, procedures for starting a steam engine occupied the first few hours of each day.

Following the rapid pace of development during the thirty years or so preceding the war, the 1920's and '30's were a time of consolidation. Size and engine power increased, diesel engines became more or less universal, as did hydraulic systems. By the Second World War construction machinery was more or less indistinguishable from that of today.

Grader

The first recognizable grader dates from 1886. It was of course animal drawn but is remarkably similar to its descendant (below) photographed in the same place one hundred years later.
Self-propulsion was introduced in 1909.
A grader in 1986.

Scraper

The Fresno scraper, very popular in its time, was the ancestor of the monsters of today, which can haul 240 cubic metres per hour over a distance of 100m.

Bulldozer

The history of the bulldozer begins with the development of the track laying vehicle. A steam-powered one was first used in the Crimea in 1854. Early models took some time to find their ideal form and it was some time before steering by differentially controlling track speed became general and allowed dispensing with a leading axle. Here it is easy to see how the internal combustion engine facilitated the marriage of form and function.
The generic term "caterpillar" was first used in 1909. By 1914 their outline was little different from those of today.
The far-reaching union of caterpillar and blade took some time. The bull board had been developed separately for animal traction.

Farm Tractor

The tractor came into being as a substitute for animal traction on the farm, whose cost was rapidly becoming prohibitive. To feed a horse for a year required setting aside two hectares, as well as an hour or more a day for care. The first recognizable tractor made its appearance in 1890. The tractor rapidly approached its optimal design just after the First World War when the engine and drive train replaced the chassis.

It had of course been preceded, notably in the UK, by the traction engine, but their weight and expense prevented them from replacing the horse in the various daily farm tasks. They were more widely used as stationary engines for ploughing (usually by cable) and threshing, often on daily hire basis.

Compactor

The UK led in the development of mechanical compactors due, probably, to the rapid propagation of macadam roads during the 19th century. The first steamrollers, manufactured by Aveling and Porter (a familiar name to any of us who are now sufficiently old to have been young enough to be enthralled by its ponderous and grinding progress, the enormous flywheel and the luridly imagined results, fed by comic strips of the period, of falling under it, were used in 1867.

These were, like steam traction engines, much exported to the US. Steam power remained popular well into the 20th century. However, the sheer quantity of work required to obtain enormous quantities of coal and water, raise steam, find more water every few hours, and simply move it from site to site resulted in its disappearance from European roads during the 1950's. They are still in use elsewhere, notably in India.