PORTS AND HARBOURS f
of modern sea transport. London and Antwerp regularly
receive vessels of 20,000 tons and over, with draughts
exceeding 30 ft.* Cargo vessels, drawing 2o ft. only, can
reach Rouen all the year round, and those drawing 23 ft.
during rather less than 200 days annually. Barges of
2,000 tons burden penetrate to Strasburg, 200 miles above
Cologne, and barges of 1,000 tons are towed by tug up to
Basle.

This increasing restriction on the size of vessels, due
to the narrowing and shallowing of the river channel,
detracts from the importance of River Ports and makes
such ports eager, if possible, to merit the title of Seaport,
which, in the loose sense in which it is now used, may be
said to apply to all ports which can receive sea-going
vessels.

Apart from these physical restrictions, a riverside
situation has other definite drawbacks to navigation.
Most rivers have tortuous courses, with awkward bends
and difficult reaches, which necessitate careful manceuvring
and a very competent knowledge of the channel. The
navigable course is necessarily narrow, and may be
thronged with small craft, which in times of fog and dark-
ness render the difficulties of navigation greater still.
The cost of deepening and regulation works is often con-
siderable, and indeed a point is soon reached beyond
which it becomes prohibitive. Glasgow is an example of
a port which has greatly improved its accessibility to
shipping. Years ago—not many in a modern sense—the
Clyde was little better than a small stream with 4 or 5 ft.
at low water. Now there is sufficient depth to enable a
ship drawing 30 ft. to reach Glasgow Harbour. But the
cost of carrying out such improvements in a river is
necessarily heavy, and it is not difficult to see that there
must be a limit to remunerative outlay.

1 The deepest draught of a vessel which has entered the King
George V Dock at London, to date, has been 36 ft. The loaded
draught of the Belgenland in the Scheldt is 32 ft. Smaller vessels
reach Antwerp with a draught of 33 ft.

I’