Chirk Tunnel and Aqueduct

Looking towards the south portal of the 421m-long Chirk Tunnel

Looking towards the south portal of the 421m-long Chirk Tunnel


3 April 2015

Chirk, Wrexham County Borough

SJ 28672 37378; 52.92904°N, 3.06254°W


Chirk Aqueduct carries the Llangollen Canal over the Ceiriog Valley, with the river below forming part of the border between Wales and England. The aqueduct was built between 1796 and 1801 by Thomas Telford during the construction of the then Ellesmere Canal. The Pontcysyllte Aqueduct three miles to the north was also later built by Telford for the same canal.

Chirk Aqueduct’s ten arches span a total length of 220m, at a height of 21m above the River Ceiriog. The waterway is contained by a cast-iron trough between the stone side walls.

Alongside the aqueduct runs a complementary masonry arched viaduct, built by Henry Robertson in 1846-1848 for the Shrewsbury and Chester Railway. At the Welsh end of the aqueduct, the canal continues northwards through the 421m-long Chirk Tunnel, built in 1794-1802.

The Aqueducts (Royal Commission on the Ancient and Historical Monuments of Wales);
Chirk Tunnel (Wikipedia)


Falkirk Wheel

Falkirk Wheel. Opened in 2002, the world's first and only rotating boat lift re-established the link between the Union Canal and the Forth and Clyde Canal.


22 December 2011


NS 85257 80131; 56.00033°N, 3.84144°W


The 35-mile-long Forth & Clyde Canal was built between 1768 and 1790 to provide a shipping route across central Scotland from the Firth of Forth in the east to the Firth of Clyde in the west. A route from its eastern end to Edinburgh — a distance of about 31 miles — was created with the construction of the Union Canal between 1818 and 1822. The two canals were connected by a flight of 11 locks at Falkirk, where their difference in height was 35 metres.

Competition from the railways spelt the demise of the canals. Commercial use of the Union Canal came to an end in the 1930s and the flight of locks at Falkirk was filled in and built over. The Forth & Clyde Canal ultimately fell into disuse in the 1960s when it was closed in order to avoid having to build a motorway crossing.

British Waterways, with support from a number of sources, including National Lottery funding via the Millennium Commission, led an £84.5m project to revitalise the two canals. The Millennium Link was the UK’s largest canal restoration project and its centrepiece was the Falkirk Wheel — the world’s first and only rotary boat lift.

The Falkirk Wheel was officially opened in May 2002 and cost £17.5m. Its overall diameter is 35 metres and its shape was inspired by a Celtic double-headed axe. Boats can transfer through the lift in about 15 minutes, with a half rotation of the wheel taking 4 minutes, during which time a water-filled gondola at the lower level swaps position with its counterpart at the upper level. The wheel is always in perfect balance due to Archimedes’ principle — a floating object displaces its own weight in water — so as a boat enters a gondola, a volume of water equal to the weight of the boat is forced out, preserving the original net weight of the gondola plus water. The energy required to operate the wheel is only 1.5 kWh, roughly equivalent to that needed to boil 8 kettles of water.

The upper level of the Wheel is connected via a reinforced-concrete aqueduct to a 180-metre-long tunnel ending in a basin which in turn connects to the Union Canal via a double lock. The Roughcastle tunnel was built when the Wheel was constructed so as not to disturb the Roman remains of the Antonine Wall, under which it passes.

The Falkirk Wheel (; Falkirk Wheel (Wikipedia)


Shropshire Union Canal, Chester

Renovated Steam Mill, close to the Shot Tower


1 October 2011


SJ 41069 66639; 53.19354°N, 2.88350°W


The main line of the Shropshire Union Canal runs from Ellesmere Port on the River Mersey to the Staffordshire and Worcestershire Canal at Wolverhampton. Now in the hands of British Waterways, the canal resulted from the mergers of various smaller canal companies.

Permission was granted in 1772 for a canal from Chester eastwards to Nantwich and Middlewich. A short section in Chester was opened in 1774 and the extension to Nantwich was completed in 1779. This was, however, a dead end, as competing interests had managed to prevent it from joining the Trent and Mersey Canal at Middlewich. It consequently met with little commercial success until a route north opened up in 1797 with the construction of the Ellesmere Canal. This ushered in a period of prosperity which saw the canal-side areas of Chester becoming increasingly industrialised. The leadworks’ shot tower and the Steam Mill are two notable surviving examples of developments from that era.

The Chester and Ellesmere Canal companies merged in 1813 and the Birmingham and Liverpool Junction Canal was also incorporated into the business in 1845. The next year the enterprise changed its name to the Shropshire Union Railways and Canal Company and took over the Shrewsbury Canal and others in east Shropshire. The company was, in turn, acquired in 1922 by the London and North Western Railway Company.

Competition from the railways led to the decline of the commercial use of the canals and the canal-side areas, once thriving centres of industrial activity, fell into a period of decay. Nowadays such areas are the subject of urban regeneration projects, with the land, and in some cases existing buildings, being reused for residential and business developments.

The Steam Mill

The Steam Mill building dates back to around 1785 and was built in three phases, with additions in the early and mid 19th century. It originally served as a canal-side warehouse and in 1864 was converted into a steam-powered flour mill. More recently, Miln’s Seeds used it as a warehouse in the 1970s and 80s, during which time it featured a seed-transport system based on blown air and gravity. It received a Grade II listing in 1985 and is now a business centre with a bar/club on its ground floor.

Shropshire Union Canal (Wikipedia);
The Chester Canal (Chester: A Virtual Stroll Around the Walls);
Former Steam Flour Mill (British Listed Buildings)