The Caldon Canal is named after the village of Caldon (or Cauldon) but doesn't go within three miles of it.
That's because Caldon and, more importantly, the limestone quarries at Caldon Low are high up in the Staffordshire Moorlands, making access by canal alone impractical.
For this reason, the Caldon "Canal" was always intended to be a canal plus a tramroad, authorised together by the same act of parliament.
The First Tramroad
The first tramroad, completed in 1778, used wooden rails topped with iron which were fixed to wooden sleepers.
It ran from Froghall Old Wharf by a steep and uneven course which, other than one or two bridges, seems to have had little engineering other than the shallowest of embankments.
Wooden railway with iron rail top
Wooden railway cross-section
As a result, the route is now quite hard to follow on the ground.
This was a railway in the modern sense, in that it used flanged wheels on a smooth rail.
In operation, however, it was rather primitive, like a single-track road with passing places.
The wagons were pulled along the line singly by horses and when another was met coming the other way, they looked for a passing place, presumably with loaded wagons heading downward taking priority.
Steepness was its biggest downfall, with some sections being almost impassable in winter.
The brittle cast-iron rails were also a problem; each one had two holes in it for fixing to the wood beneath and a triangular tongue at one end which fitted into a notch in the following rail.
Despite being wider around the holes, the rails would frequently snap at these points and the triangular tongues were liable to break off.
The Second Tramroad
The second tramroad addressed the most serious problem of its predecessor by being better engineered.
To begin with, the canal was extended via the new Froghall Tunnel to its current terminus at Froghall Wharf, where a new basin was dug.
This allowed a less severe incline to be cut out of the valley side through Harston Wood and on across Whiston Common.
Low embankments, much easier to spot in the landscape today, also helped to even out the route.
The railway itself, however, employed the same technology and operating practices as its predecessor and suffered from the same problems.
Even the improved inclines were still difficult in bad weather.
A change of technology was needed.
The Third Tramroad
The third tramroad, designed by the great Scottish engineer, John Rennie, and opened in 1804, was a major change in approach.
The new route was divided into heavily-engineered inclines and flat sections.
The flat sections were horse-drawn, as before, but with two tracks; one for up and one for down and with wagons martialled into trains, rather than hauled individually.
The inclines were "self-acting", which is to say they were powered by gravity.
Wagons descending the incline loaded with limestone were connected to empties at the bottom via chains and pulley wheels so that the heavier loaded wagons would pull the empties up.
In operation, some of these "empties" were loaded with coal for, amongst others, the copper smelter at Whiston.
This was done at least partly to avoid road tolls, causing the local turnpike trust to complain that "revenue was cut by carriage of Coals in the Reelway".
The line itself was a plateway, in which, in contrast to a railway, a smooth wheel runs on a flanged rail or "plate".
The plates were mounted on stone sets, rather than sleepers, to allow easy passage for horses in between.
The plates had a notch at each end.
An iron spike, fitting the notch, was driven into a wooden plug, itself driven into a hole in the stone, securing the plates in position.
John Farey gives a contemporary account of the plateway in his "General View of the Agriculture of Derbyshire"
which has been digitised by Google.
Relics of the Consall Plateway, built on the same principles, can be seen at the visitor centre in Consall Nature Park.
The Wikipedia entry for the Little Eaton Gangway
includes an early 20th century picture of a plateway in action.
The Caldon Low plateway seems to have used flat-flanged plates, rather than the inverted fishbelly (curved flange) used at Little Eaton.
Although it was a huge improvement on its predecessors, the plateway had its problems.
In particular, the cast-iron plates were brittle and liable to snap under heavy loads.
Over time, the stone sleepers also became deeply worn (as can be seen in the example below) and, by the 1840's, it was time for a replacement.
The Fourth Tramroad
The fourth tramroad, designed by local engineer James Trubshaw, was the most heavily engineered of them all, consisting of a series of self-acting inclines running all the way from the quarries to Froghall Wharf.
The horse-drawn flat sections of Rennie's plateway were dispensed with.
Where necessary, substantial embankments and cuttings were constructed to keep the incline more-or-less constant and the final section, leading to the quarries, included a tunnel.
The technology used this time was that of a modern-style railway, with flanged wheels running on smooth rails.
The top section of each incline used a three-rail layout, in which the centre rail was shared by the up and down lines.
Half-way down the incline, the centre rail divided into a conventional double track layout, to form a passing loop.
Below the passing loop, the line was single-track, accessed by a point which was set automatically by the descending wagons.
Trains of climbing and descending wagons were linked by a cable which ran on a series of rollers and guides along the centre of the tracks.
At the top of each incline the cable passed through a braking system which controlled the trains' speed.
A similar system was still in use on the Corkickle Brake Incline
, at Whitehaven in Cumbria until 1986.
The Caldon Low version, however, closed in 1920 and limestone to be carried by canal was, instead, loaded from standard-gauge wagons at a new basin near Endon.
Deliveries to the limekilns at Froghall continued by road into the late 1930s.
Lower Froghall Plane
Brake Drum Head On
The short inclined plane leading into Froghall Wharf was used by both the third and fourth lines.
The system used was different from the other inclines but worked on similar principles.
Two cables were wrapped opposite ways round a horizontal brake drum.
A full wagon was let down on one cable which would unwind from the drum.
Meanwhile, the other cable would be winding on to the drum and pulling an empty wagon upwards.
The rate of travel would be controlled by a man operating a braking mechanism.
The incline was relatively shallow by the standards of the 1804 line but was steep by the standards of the 1847 replacement.
This proved awkward in operation but proposals to modify it were never carried out.
All that remains today are the stone foundations for the drum.