The rapid growth of industry and population that occurred in Glasgow in the mid-Victorian years had a devastating effect on the river Clyde. The infrastructure for handling industrial and human waste was limited to gravitation, ending in the river, and the river itself became an open sewer. The problem was studied throughout the 1850s and 1860s but it was a major Parliamentary report by Sir John Hawkshaw in 1876 that focused attention on potentially workable solutions. At the time, Glasgow had a new supply of excellent water from Loch Katrine that supplied 36 million gallons of water annually. Hawkshaw suggested a new system of intercepting sewers that would convey effluent to areas on the margins of the city where it could be treated. There was a suitable location on both sides of the Clyde below Whiteinch where the effluent could be treated with alum, lime and charcoal to precipitate the solids and deodorize the water so that it could be discharged to the river. Existing methods for disposing of the resulting solid waste relied on methods where it might be used to fertilize land but this was not practicable. Disposable in deep tidal water off Cloch Point, Farland Head, or Irvine Sands was suggested as more suitable areas for discharge.

It was not until 1894 that the first sewage treatment works was opened at Dalmarnock. A decade later, works were opened at Dalmuir and the location now allowed the slurry precipitate to be removed to deep water off the mouth of Loch Long and later off Garroch Head by a purpose-built ship. The first of these vessels, Dalmuir, was built by Messrs William Beardmore & Co. Ltd., at Govan. She was 234 ft long and at 555 tons net, could handle 1,200 gallons of sludge on each voyage. The tanks on the vessel were filled at Dalmuir and then discharged at the deep-water destination. In 1910, another works was opened at Shieldhall, serving the south side of the city, and an attendant “sludge boat”, Shieldhall, was built by Beardmore’s at Dalmuir. She was 261 feet long and larger than Dalmuir at 747 tons net.

Shieldhall

Shieldhall, dressed off Old Kilpatrick  leaving a trail of smoke for Isle of Arran

Shieldhall loading at the treatment works

A view of Shieldhall from the air around 1935

The cleansing of the Clyde that resulted from these developments in addition to others carried out in the smaller towns and burghs that lined the river, led to a great improvement in sailing “doon the watter”.

In the early 1920s, Dalmuir was sold and was replaced in 1925 by Dalmarnock, from the yard of Messrs Simons & Co. Ltd or Renfrew in 1924.

Dalmarnock fitting out at Renfrew

Dalmarnock at Shieldhall

Dalmarnock off the mouth of Loch Long in 1935

She was of similar dimensions to Shieldhall, and together, the two vessels served the needs of the sludge trade until Shieldhall was replaced by a new steamship of the same name in 1955.

The new Shieldhall

The new Shieldhall came from the yard of Messrs Lobnitz & Co., of Renfrew and is now preserved on the Solent after she was replaced by a motor vessel, Garroch Head from the yard of Messrs James Lamont & Co. Ltd., of Port Glasgow in 1977. Dalmarnock was also replaced by a new motor vessel of the same name from the yard of Messrs Lamont in 1970.

M.V. Dalmarnock passing Erskine