How the tramp steamer evolved
Coals from Newcastle
The revolutionary John Bowes
Until the 1850s, steam ships carried almost exclusively passengers, mail and relatively high value and often perishable cargo such as livestock. Steam ships were too expensive to build and run to compete with sailing ships for carrying bulk cargoes such as coal and stone. These cargoes did not deteriorate during a voyage that might be protracted by adverse weather, especially in the winter.
In 1852, a ship was built that began to change all this. The steamer John Bowes, a modest 150 feet long, was launched by Charles Palmer at Jarrow on the River Tyne. Palmer had interests in a series of collieries in County Durham, and the John Bowes was designed to deliver coal from the Rivers Tyne and Wear to the Thames. Because it was largely independent of wind and tide, the John Bowes could make the round trip in a week. In a year it was reckoned to do the work of about ten of the collier brigs which dominated the east coast coal trade.
The importance of water ballast
The key feature which allowed John Bowes and the screw colliers which followed it to compete so successfully with the much cheaper sailing ships was the facility to carry water ballast. When a sailing collier arrived on the Thames and discharged its coal, it had to take on board ballast in the form of sand or shingle so that it was stable for its voyage north to the coal ports. The ship had to queue to load ballast, pay for it and, when it arrived at Newcastle or Sunderland, pay for it to be shovelled out. This was all too time consuming for a screw collier, which could only trade profitably if it could make more voyages than a sailing collier. The system devised was to fit tanks below the hold that could be filled with water once the ship was discharged. This water ballast maintained the screw collierís stability during the northbound voyage. On arrival off the Tyne or Wear, a pump running off the engine simply emptied the water ballast tanks, and the screw collier was ready to take on another coal cargo. This was a very elegant and relatively cheap solution to an age-old problem. Indeed, so good was the idea of water ballast that almost every steam and motor cargo ship built for the bulk trades since has had a similar system.
After the John Bowes came a whole fleet of steam colliers which quickly took over the important trade in coal to London. Similar, slightly smaller ships were built for the coastal trade all round the UK and to near-continental ports, the steam coasters. But arguably the most important type of vessel which evolved from John Bowes was the ocean-going steam tramp.