carried as well. Richborough was not the only port used, a small proportion of the traffic being to and from Purfleet and other ports on the Thames and Medway. On the French side the only ports with inland waterway communications were Calais and Dunkirk in the N. and ports on the Seine farther south.
The I.W.T. service in ( Ireat Britain also undertook a certain amount of transport over British canals, but the total traffic moved during 1918 only amounted to about 150,000 tons, of which the transport of oil on the Forth and Clyde canal accounted for 130,000.
The towage of craft from home to the various theatres overseas demanded of the I.W.T. directorate careful organization, and involved the solution of many problems; during 1917 nearly 700 shallow-draught river craft were despatched to Mesopotamia alone.
France and Belgium. The extensive system of waterways in France and Belgium naturally suggested the use of I.W.T. for military purposes, and a beginning was made in Dec. 1914 by the hiring locally of a few barges for loading with supplies. In Jan. 1915 an establishment was sanctioned and some 36 craft of various kinds were ordered. The service eventually undertook much miscellaneous work, but at the outset its main work consisted of the carriage inland of traffic of no great urgency, such as forage, timber, bricks, stone, sleepers, trench material and ammunition, a large proportion of the traffic being received on barge direct off ship. Another branch of its work was the carriage in ambulance barges from the front of seriously wounded patients unable to stand the jolting inseparable from a journey by train. Another development was the provision of water- supply units, each of six barges, equipped with plant for treating water of doubtful or dangerous quality by filtration and chemicals, thus ensuring a supply of potable water at any point on the inland waterways. Each unit was in charge of an expert chemist and was capable of dealing if need be with poisoned water supplies. A num- ber of floating bridges were constructed so that communication could be opened rapidly across any waterway. Provision was also made for the reopening to navigation of waterways previously in enemy hands, a number of lock gates of special design being among the materials provided for use when required.
During the later stages of the war the necessity of relieving the strain on the French railways led to increased activity on the part of the I.W.T. service. In the winter of 19167 its construction branch built or enlarged eight large wharves. It also constructed its own workshops and dry-docks for the repair and maintenance of craft. On the German retreat in March 1917 it repaired and reconstructed the banks, locks, sluices, and removed the obstructions, on the re- covered portion of the Somme ; after the battle of Arras it reopened the river Scarpe to navigation between Arras and Fampoux. Both in 1916 and 1917 a large amount of pumping was done in connexion with strategic inundation and drainage.
Although the whole of the French and Belgian waterways are linked up, the connexions between those in the N.W. and the remainder were in the hands of the enemy throughout the war, and the only means of communication between She canals in the N. and the Somme and the Seine was by sea. During 1918 a regular service of coastal barges was instituted to ply between the northern canals and the Seine. Much work was done for the French and Americans, coastal trips being worked for the former and craft with crews being lent to the latter to ply on the Seine.
The waterways used varied in size from small creeks up to ship canals, but what may be considered the standard canal was 2 metres deep with 3-70 metres head room under bridges, locks 38-84 metres long and 5-20 metres wide. The standard type of barge in use in northern France has a draught laden of I -80 metres, beam 5 metres and length 38-50 metres; the maximum height above water-level is 3-20 metres, giving a margin of -50 metre under bridges to allow of slight variations in the water-level in flood time. The carrying capacity is 280 deadweight metric tons, but the space below hatches (being only about 300 cubic metres) governs, in the case of cargoes of light substances, the tonnage that can be transported, the very limited head room available preventing the carriage of cargo above deck. The British fleet included many self-propelled barges; these carried only 130 tons, but saved time at locks by not having to await the passage of the rest of a convoy. Navigation is not practica- ble in the dark, and may be interrupted by floods, ice, gales, or fog.
Egypt. Up to the beginning of 1917 such military water transport as was used was controlled by the Royal Army Service Corps. In March of that year an I.W.T. organization was set up of which the principal objects were to relieve the pressure on the railways, to undertake lighterage at the ports of Alexandria and Port Said, and to eliminate competition between Government departments for craft.
The chief waterways operated on were those of the Delta, the Suez Canal, the Ismailia Canal, and the upper Nile, while the bulk of the craft employed were hired locally, only some 50 tugs and barges being obtained by the I.W.T. service from Mesopotamia and England. The principal traffic carried was grain and forage, but a considerable number of passengers were carried as well. Services were run between Cairo and Kantara, Cairo and Alexandria, and Assuan and Cairo. The lighterage work at the ports increased steadily, and by the last quarter of 1918 was greatly in excess of the inland water transport work.
, Mesopotamia. In Sept. 1916 the control of river transport in Mesopotamia, up till then in the hands of the Royal Indian Marine,
was transferred to the War Office and an I.W.T. organization was set up. The great length and vital importance of the waterways, their physical conditions, the great distance of the theatre of war from home and the lack of suitable personnel, materials and ap- pliances in the theatre resulted in the growth of the I.W.T. service to a size unequalled in any other theatre, and in a much wider range of activities than was the case elsewhere. The distance from Basra to Bagdad by road is 346 m., by river 498, and up to the beginning of 1917 the waterways provided the only possible means of transport on a large scale. The first railways laid in thistheatre commenced to work early in 1917, but up to the close of the campaign there was no through connexion by rail between Basra and 'Bagdad, and car- riage by water was the main form of transport employed on the L. of C. ; the railways on the L. of C. eased the extreme pressure on the river transport but did not replace it, never effecting more than one- third of the total transport required.
The physical conditions of the rivers rendered water transport on a large scale very difficult. Both the Tigris and the Euphrates are shallow with tortuous and shifting channels; navigation is liable to interruption by floods, low water, strong winds and fog. In the stretch of the Tigris known as the Narrows, extending over a dis- tance of 15 m., the average width of the river is only about 300 ft., and the depth never exceeds 7 ft. as the river overflows its bank when water-level reaches that height above the bed. Over a length of 29 m. vessels proceeding up-stream have to tie up to the bank to allow descending vessels to pass. The requirements of craft in order of priority were shallow draught, strength and power of towing, accommodation for passengers, fuel and cargo capacity. The larger self-propelled craft were paddle or stern-wheel steamers or motor vessels from 130 to 220 ft. long, beam up to 35 ft., draught from 3 ft. 6 in. to 5 ft., speed 6 to 12 knots, average deadweight load about loo tons. The largest dumb barges, 170 ft. long and 25 ft. beam, carried 200 tons at 3 ft. draught. The number of cots on ambulance vessels varied from 100 to 200 according to the type of vessel. The general conditions and the trying climate demanded of the I.W.T. service the provision of numerous varieties of special craft, such as refrigerator, ice, cold storage, filtration, water and oil storage barges, hydro-glisseurs for despatch service, motor launches and other vessels. The distance from home, some 6,220 m., rendered the trans- fer to the theatre of lightly built shallow-draught vessels a matter demanding very careful prearrangement ; while the voyage from India across the Indian Ocean, always dangerous, was practically impossible during the monsoon. For the erection of craft sent out in parts, and for the maintenance of the large fleet eventually built up, extensive and well-equipped dockyards and shops had to be pro- vided, together with slipways, wharves, storehouses and camps for the numerous personnel.
The organization of the service underwent various modifications due to changing conditions; the work was eventually divided among 13 branches, viz. craft reerection, marine engineering, dockyards, vessels, buoyage and pilotage, construction, conservancy and rec- lamation, port traffic, transport, native craft, stores, accounts, personnel. The craft reerection branch assembled and launched craft imported in sections. The marine engineering branch decided what hull and machinery repairs were necessary and controlled engine-room personnel and stores; the vessels branch controlled deck personnel and deck stores and fittings. The dockyards branch fitted out vessels arriving from overseas and carried out the repair and maintenance work called for by the marine engineering branch. The main yards were at or near Basra, but there were subsidiary yards and floating repair shops at the principal I.W.T. depots inland. The buoyage and pilotage branch was responsible for facilitating navigation by making fluvial surveys, compiling of sailing direc- tions, marking channels by buoys and beacons, providing pilots, salving sunken craft and refloating stranded craft. This branch un- dertook minor dredging work, and during the low-water season em- ployed the process known in India as " bandalling," by which temporary training walls of matting fixed on bamboos are constructed to divert water into the particular channel which it is desired to deepen by scour. Reaches particularly subject to shifting silt banks were examined daily, the channels re-marked when necessary, and the available depth of water notified to the loading points. The work of the construction branch was very extensive, including the con- struction of wharves, jetties, dockyards, workshops, fuel depots, camps, etc., with a great variety of incidental works, such as pumping stations, power houses, pipe lines and a score of bridges, including the bridge at Amara and the Maude bridge at Bagdad. The conserv- ancy and reclamation branch was responsible for heavy engineering work for the improvement of navigation and for the reclamation of low-lying areas at Basra to provide sites above flood-level for camps and depots; for about a year it was also responsible for irrigation. On the Tigris by means of dams and spurs the depth of water at the Narrows was increased, some dredging was done, and bunds breached by the Turks were repaired. On the Euphrates side about 24 m. of channel was dredged to give communication by water between Basra and Nasiriya. The native craft branch controlled the fleet of vessels hired locally. Some had been hired as early as 1915, but in Jan. 1917 all such craft of over 12 tons' capacity were requisitioned and some 50 of them were converted into motor vessels by the fitting of old motor-car engines. The fleet of native vessels did much useful
