Timber viaduct at Combe
Despite Cornwall's distance from London and the industrial north of England, some of the earliest railways were built in the region. Most were horse drawn and hauled only mineral traffic for many years. Two railways are of particular relevance to a history of the Broad Gauge - the West Cornwall Railway and the Cornwall Railway.
In 1834 the Hayle Railway obtained an Act of Parliament to build a standard gauge railway between Hayle and Redruth (9¾ miles - 15½ kms) with a number of short branches. This railway was opened in 1837, although a passenger service did not commence until 1843. In 1846 the West Cornwall Railway obtained its Act, which gave it the right to purchase the Hayle Railway and extend it at both ends to connect Penzance and Truro (25 miles - 40 kms). The Act also enabled the deviation of the existing line to avoid two steep inclines at Angarrak and Penponds. The railway was authorised to build a broad gauge line with a standard gauge rail to be added if a standard gauge railway was built that connected Truro with the rest of England.
The financial troubles of the late 1840s meant the West Cornwall Railway immediately ran into financial difficulty and many shareholders refused to pay calls on their shares. Enough money was raised to begin work, but in order to save the cost of converting the Hayle Railway to broad gauge, the whole line was constructed to standard gauge. To save money Barlow rails were used as this avoided the use of sleepers to hold the track in position, but, as the company later discovered, they frequently caused derailments and had to be replaced.
The line was completed in 1852 and the West Cornwall Railway made a small profit for a few years. However, its Act of Parliament required a broad gauge rail to be added if another railway required it. The construction of the broad gauge Cornwall Railway between Plymouth and Truro meant that by the end of the 1850s the West Cornwall Railway was required to add a broad gauge rail. The company lacked the money to do this and so sought an arrangement with the three main broad gauge railways - the Great Western Railway (GWR), Bristol & Exeter Railway (BER) and South Devon Railway (SDR). In exchange for a lease over the West Cornwall Railway, the three companies paid for the broad gauge rail to be added, and broad gauge passenger trains ran into Penzance from March 1867. The West Cornwall Railway was eventually merged into the Great Western Railway in 1876, although it continued to have a paper existence until 1947.
The Cornwall Railway was authorised to build a broad gauge railway between Plymouth and Falmouth (then a major sea port). Like the West Cornwall Railway, the Cornwall Railway obtained its Act of Parliament in 1846, and immediately ran into financial difficulties when the depression of the late 1840s set in. Little or no attempt was made to construct the line for a number of years . In 1851, Brunel advised the directors that by reducing the proposed double line to a single line railway and abandoning some of the proposed branches, the railway could be built at a much lower cost. The route was through hilly country and in order to avoid steep gradients, missed several towns which could have provided local traffic. In addition to 34 timber viaducts, the main engineering work was the 730 yard (674 metre) Royal Albert Bridge across the river Tamar at Saltash.
The Cornwall Railway started construction of the section between Truro and St Austell, but it was not until the GWR, BER and SDR agreed to guarantee the dividends on preference shares (in exchange for a lease on the line), that enough capital was raised to build the line between Plymouth and Truro. Plans to construct the section between Truro and Falmouth were temporarily abandoned.
The line between Plymouth and Truro was opened in May 1859 with 5 passenger trains each way per day stopping at all stations - a journey of 2½ hours between Plymouth and Truro. The section between Truro and Falmouth was finally opened in August 1863, by which time the Cornwall Railway was so financially dependent on the GWR, BER and SDR that it had virtually no control over its own line and never paid a dividend on its ordinary shares. In November 1876, the Cornwall Railway was absorbed into the Great Western Railway.
By the early 1870s it was clear that the broad gauge had no future and all engineering works (principally replacement of some of the timber viaducts) anticipated conversion to a standard gauge railway. In 1877 the last broad gauge line ever to be built was opened between St Erth and St Ives. Unlike lines further east, no lines in Cornwall were converted to standard gauge until the weekend of 21/22 May 1892, when the whole broad gauge network came to an end.