The line was electrified as part of a modernisation scheme in 1960, and it continues today as the trunk of the North Clyde network west of Glasgow.
The communities of Dumbarton and Helensburgh were important staging points on the road from Glasgow to the western seaboard of Scotland, and were well served by small boats on the River Clyde.
Towns served by the new railway immediately felt the advantage, as the necessities of life, particularly coal and lime for farm use, became much cheaper, and the transport to market of locally manufactured goods was also immeasurably improved.
[2] The C&DJR line was remarkably successful, and that only emphasised the potential of a railway that truly connected the area north and west of Dumbarton with Glasgow.
Trains would use the Queen Street passenger terminus and Sighthill goods depot of the Edinburgh and Glasgow Railway.
[2] When the construction was nearly complete, a disagreement with the Edinburgh and Glasgow Railway arose over the terms of using the Queen Street station.
Instead of using that company's terminal facilities, on opening day the GD&HR trains ran to the Caledonian Railway Buchanan Street station from Sighthill.
[3] Steamer operators had run from Glasgow to Bowling Pier for the onward connection over the C&DJR; that was now futile because of the through railway route, and many of them switched to operating throughout from Glasgow to Dumbarton and River Leven destinations in direct competition with the railway; they had to reduce their fares drastically in view of the speed disadvantage they suffered.
The GD&HR had intended to operate onward steamer connections from Helensburgh to the Clyde Estuary locations in 1858, but they discovered that the Caledonian Railway, established at Greenock on the south bank, had chartered all the available vessels and were monopolising the service from their own side of the river.
[5] On 15 May 1882 a new pier was built at Craigendoran, a mile or so east of Helensburgh, and a short railway spur there gave a direct connection.
[5] The line had previously run dead straight approaching Helensburgh (approximately along the alignment of the present day Marmion Avenue and Monaebrook Place) but to accommodate the Craigendoran Pier station adjacent to the through line, a new southerly sweep was introduced and the old straight route abandoned.
The line was not planned as a suburban railway; in fact the first station on leaving Glasgow was Maryhill, then an isolated rural town, followed by Dalmuir.
[2] Responding to the shortcomings of quay facilities in Glasgow, the Clyde Trustees undertook an ambitious project from 1871 to build a large dock at Stobcross, on marshland on the north bank downstream.
[8] The North British Railway wished to access these new industrial developments, and foreseeing the demand for mineral transport in connection with the construction of the Queen's Dock, built a connecting line to it, the Stobcross Railway, leaving the GD&HR line at Maryhill and running south and then east.
In 1874 the short Whiteinch Railway was opened, leaving the Stobcross line near Jordanhill, and running to an area of industrial development on the Clyde.
The pattern of developing heavy industry to the west of the city was increasing, to satisfy the demand for more spacious sites and easy access to the Clyde for river transport.
For shipbuilding purposes, access to a wider section of the Clyde was important as the vessels being produced were larger in size than in the past.
It left the Stobcross and Whiteinch lines near Jordanhill and ran west close to the Clyde, to a terminus at Clydebank.
A compromise was reached by which the L&DR would build only as far as Dumbarton and the line from there to Balloch would be made joint between the NBR, the LD&R, and the Caledonian Railway.
[5] Up until this time the GD&HR route and the associated branches had formed a developing outer suburban network of the North British Railway.
[2] A new station was built further north on the relocated GD&HR main line and renamed Singer, and the name is retained to the present day.
[2] However both routes were run down, and the post war surge of better public transport by bus, and the rise in private car ownership, coupled with the beginning of the decline of the heavy industries on Clydeside, meant that change was inevitable.
In the westbound direction the Arrochar train started in the Pier station and ran east to the junction, reversing there to continue its journey.
Balloch Pier was on Loch Lomond and in the nineteenth century it was the scene of considerable transfer traffic from steamers to trains.