Limestone Link History

Introduction

This page describes the geological and historical background for features seen along the length of the Limestone Link. Further topics more specific to individual stages are covered in the relevant page for that stage.

Geology of The Limestone Link

Most of The Limestone Link is within an area between the River Avon to the north and the Axe valley. The north of Somerset is dominated by the Mendip Hills, an area of outstanding natural beauty, stretching from Frome in the east to Crook Peak in the west. The highest point is Black Down at 324 metres (1,063 ft).
To the north of Bath are Lansdown, Langridge and Solsbury hills. These are outliers of the Cotswolds. Bath is noted for its thermal waters (48 °C) that are rich in calcium and sodium sulphates.

The main geological component of the Mendips is Carboniferous Limestone. It represents the remnants of a much higher range of hills that existed hundreds of millions years ago. There are a wide variety of caves and swallet holes caused by dissolution of the rock by water. Indication of a shallow marine sea are provided by sediments yielding fairly rich fossil fauna. The heavy rainfall on the hilltop sinks down through the limestone to emerge as springs at the bottom. Except for Blackdown - highest point of the Mendips which is not limestone - there is almost no surface water on top.
Coal measures appear in the Radstock district, and surrounding Somerset Coalfields. Locally the beds are folded and faulted. There were mines in the North Somerset areas but these have closed.
The Mendips were mined for lead, silver, coal, ochre, fuller's earth and zinc but this has finished. They were also quarried for stone, notably at Bath of Oolite Limestone. Today the Mendips are a major source of aggregates.
This was one of the first areas in the world to undergo systematic geological study and mapping by John Strachey and William Smith in the 18th century.
William Smith worked with John Rennie surveying the route of the Somerset Coal canal. During his time as surveyor Smith devised a system of dating and sequencing rock formations by their fossil remains. This system was the start of the science of geology, earning Smith the title “Father of Geology”.

North Somerset Coal Field

The Somerset Coalfield in northern Somerset, is an area where coal was mined from the 15th century until 1973. It is part of a larger coalfield which stretched into southern Gloucestershire. Reputedly it contained more geological faults than any other coal field in England. The seams in the North Somerset coalfield were very hard to work as they were thin (2 feet thick or less), often faulted, and not always of the best quality. Many mines only lasted for a short time before extraction became too difficult and unprofitable. There were about 80 pits, not all working at the same time. Mining was going on quite extensively in the 16th and 17th centuries, but by the 1790s deeper pits were being sunk. Transport was a problem until the Somerset Coal Canal and the Radstock tram road opened. The peak years were 1900-1920 but mines were not modernised. In 1920, 1.75 million tonnes of coal were mined at 26 pits and 7,387 people employed. By 1947 when the pits were nationalised, 13 pits produced 0.5 million tonnes, employing 3,000 people. By 1957 only five pits remained and the last one closed in September 1973.
Some of the pits you will walk past along the route are:
1. Dunkerton. ST. 699 586. It was the largest in Somerset with the worst reputation for working conditions and disregard for safety. There were riots in 1908-09. Railway sidings were built c.1906. By 1912 over 700 miners worked the pit. It closed in 1927.
2. Camerton. Two pits were mined at Camerton. Old Pit (ST 679 581) being the original, was opened in late 18th century and worked until 1898. Camerton village sits in a deep valley and the pit head was on a steep slope making it very difficult to haul coal out of the valley. The creation of the Somerset Coal Canal was a huge relief to the transportation problem. In 1800 a second pit was sunk only half a mile to the east (ST 687 580.) Known as New Pit it remained open until 1950. It benefited from a steam winding engine which winched coal up the northern hill (Red Hill) to a wharf were it could be transported by road. The old winding house is still standing. In 1893 a large explosion killed two men. Both pits were owned by the Stephens, and later Jarrett, family who lived at Camerton Court until 1911.
3. Lower Conygre. ST. 674 584. This pit was sited just north of the hamlet of Radford and south of the village of Timsbury. It was the second pit to open in Timsbury and was joined underground to Upper Conygre Pit. Opened in 1848 it benefited from the use of the Somerset Coal Canal and the railway; having a wharf on the canal and later a siding for the railway. Coal from the Upper Conygre Pit was transported underground to the lower pit to make use of the canal. Good quality coal was mined in Upper Conygre. Eight men died in an explosion in the tunnels joining the two pits. Conygre = rabbits warren.
4. Radford. ST 661 581. This pit opened in 1793 and closed in 1847. It sat on the north side of the coal canal and had a tram road to the canal wharf. Evidence of the wharf as still visible today whilst walking from Radford to Paulton Basin. The spoil heap, shared with Withy Mills pit is now wooded and sits on the north side of the disused canal. Radford pit was 1,152 ft deep.
5. Withy Mills. ST 660 578. Opened by 1815 and closed by 1877. In 1850 nine men were killed. The land was leased by William Rees-Mogg
6. Paulton Engine Colliery ST 658 574. Opened before 1750, next to the site of the Paulton Brass and Iron Foundry. Four men and a boy were killed when a rope broke in 1830. It closed in 1830.
7. Goosard Pit (Paulton Lower Engine). ST 656 576 Also known as Gooseward or Goosewardsham Pit. Stood on the site of what is now the sewage works for the village of Paulton. It opened in 1708, possibly one of the earliest in the area.

Somerset Coal Canal

Owners of the coal mines met in December 1792 to consider the construction of a new canal to take coal to the city of Bath, which was the main market for the coal. Coal had been hauled to Bath by pack horse and mule up the hills south of Bath on poorly maintained roads. The canal was planned to take coal from the coalfields to the Kennet and Avon Canal at Dundas. The line and level of the canal was determined by the famous engineer John Rennie and in 1794 an Act of Parliament was passed. Rennie appointed William Smith to take levels of the canal and in 1795 he was appointed surveyor to the canal.
William Smith lodged at Rugbourne Farm, High Littleton from 1791 – 1795 whilst surveying the nearby Mearns coalmine. From 1789 to 1795 he lived at Tucking Mill House. He opened a Bath Stone quarry and built a railway to transport the stone to a water powered stone sawing facility at Tucking Mill. He devised a saw-frame to cut and dress the stone for building and sent it to all parts of the country by canal boat.
The canal went as far as Paulton, but a second branch from Midford to Radstock was planned. However the locks up from Midford were never built and a horse drawn tramway was used instead. The canal basin at Midford was the junction of the tramway and canal, it had wharfs, a weigh house and a long low aqueduct to carry the coal over the Cam Brook into this basin to join up with the tramway.
There was a considerable drop along the route so a boat lift, or caisson, was tried out to raise and lower boats. This was sited near Caisson House, Combe Hay. The box (or caisson) was watertight and held the complete barge. In 1799 successful trials of this were watched by the Prince of Wales but later the idea had to be abandoned and an incline was constructed by Benjamin Outram. The incline can be seen by walking along the road towards Combe Hay a short distance at ST 746604. This involved transferring the coal twice and so a flight of 22 narrow locks was built east of Combe Hay instead, opening in April 1805. Walking the route north west from ST 746604 towards Engine Wood provides a view of the locks. The engine was probably sited in Engine Wood. Caisson House was built in the late 18th century for John Smith, alias Leigh, and lived in from 1813 by the William Hills, father and son, engineers to the company. The father died in 1868 aged 92 and was buried in Combe Hay churchyard. His son retired in 1882 aged 70. To the west of Combe Hay there was a tunnel nearly 200 ft. long.
By 1850, 23 pits were joined to the canal by tramroads. It was extremely prosperous until the 1870s when the Bristol & North Somerset line opened to Radstock. In 1883 this line opened a 3.5 mile long branch from their line at Hallatrow to serve the Camerton collieries, duplicating the line of the canal. Another reason for the Somerset Coal Canal decline was its dependence solely on the collieries, and many of the original pits had closed. So the canal ceased to be used in 1898 and in 1904 the Great Western Railway bought it and built a railway, using the canal route wherever possible.

Camerton and Limpley Stoke Railway

This railway line ran from 1907 and joined the Hallatrow branch at Camerton. It crossed the Cam Brook at Midford branch and used the canal tunnel at Combe Hay, having stations at Dunkerton and Monkton Combe and halts at Radford (Timsbury,) and Combe Hay. Later halts were opened at Paulton and Midford. This single line joined the Great Western Railway at Limpley Stoke. Although a few passenger trains ran, the railway was mainly a coal outlet. Fortunately, some new collieries were opening at this time. Whilst walking the Limestone link from Midford to Hallatrow you will frequently see evidence of the railway line.
In 1952 the film, 'The Titfield Thunderbolt' was filmed using Monkton Combe Station, and sections of the line at Dunkerton and Combe Hay.