International Engineering Congress (1901 : Glasgow.

Report of the proceedings and abstracts of the papers read online

. (page 7 of 37)
Online LibraryInternational Engineering Congress (1901 : GlasgowReport of the proceedings and abstracts of the papers read → online text (page 7 of 37)
Font size
QR-code for this ebook

of Lake Onega to maritime navigation, and the third the junction
of the two seas. The completion of each of these stages of the
work would bring about great industrial and commercial progress
to Russia and to the whole of Europe.

The following members took part in the Discussion: Baron
Quinette De Rochemont, Mr. W. H. Hunter, Mr. William Brown,
Mr. S. Mavor, Mr. C. H. Moberley, and the Chairman. The
author replied, and on the motion of the Chairman a vote of thanks
was accorded to him.



Paper by J. A. OCKERSON.


THE Mississippi River is 2500 miles in length, and its drainage
area covers 1,256,000 square miles. The regulation and control
of a stream of such magnitude involves problems which greatly
tax the ingenuity and skill of man to solve. In the lower half of
the river the extreme oscillations of stage between low and high
water amount to 53 feet; and the volume fluctuates from 65,000
cubic feet per second at extreme low water, to two million cubic
feet per second at flood stages. This portion of the river flows
through an alluvial bed of its own formation, and the banks are
constantly being eroded by the action of the current. This erosion,
coupled with the suspended matter brought down by the tributary
streams, furnishes the material for sand bars, which at low stages
become formidable obstructions to navigation. The regulation
and control, then, involve two distinct problems : one the control
of floods, and the other the improvement of navigation. Incident-
ally, the works constructed for flood control have considerable
influence on the channel, by preventing a dispersion of the waters,
and thus inducing a scouring effect which tends to produce uni-
formity in depth.

The erosion of the banks reaches enormous proportions. In
the 885 miles of river lying below the Ohio River, it amounts to
an average of 9^ acres for each mile of river each year, or a volume
of 1,003,579 cubic yards each year for each mile of river; or a
total annual erosion in this 885 miles amounting to ten square miles
86 feet deep.

The alluvial basins subject to overflow cover an area of about
30,000 square miles. It has a soil of remarkable fertility, capable
of sustaining a large population. In order to utilise this land, it
must be protected from the ravages of the floods. This is accom-
plished by means of levees, or earthen embankments, built as near
the river as consistent with the stability of the banks. At the
present time, there is a total length of about 1450 miles of levee.
The average height is something over 12 feet. The levees are
built with a crown of 8 feet, and side slopes of 3 to i. High


levees are reinforced with a banquette of earth on the land side.
The whole is sodded with a very tenacious grass, known as Bermuda
grass. About fifty million dollars (over ; 10,000,000) have been
spent on the levee system, and much work remains to be done
before it is completed.

The interruptions to navigation due to low water cover a period
of about three months in each year. During the greater part of
the year, depths of 14 feet, under natural conditions, can be relied
upon; furthermore, the obstructing bars cover only a small portion
of the total length. To open channels through these bars,
hydraulic dredges of large capacity have been designed, and have
been used to good effect. It seems certain that a channel of nine
feet or more can be maintained, under the most unfavourable
conditions, by this means. The essential features of such a dredger
are a double suction centrifugal pump, with runner of 7 feet or
more in diameter; a water-jet agitator to loosen up the material;
a floating discharge pipe about 32 inches in diameter; suitable
winches for manipulating the dredger and suction; motive power
and paddle wheels for moving the dredger from point to point
under its own steam; all mounted on a steel hull carrying the
boiler, machinery, and a cabin for housing the same, and the crew
which operates the dredger. There is also a well-equipped
machine shop for making repairs, an electric light and refrigerating
plant, steam steering gear, and other accessories. These dredgers
have a capacity of about 1000 cubic yards of sand per hour, de-
livered through 1000 feet of discharge pipe. They have been in
operation for several years, and are regarded as successful.
Dredging in a stream with sand bars that shift more or less with
every change of stage, is only regarded as a temporary expedient
in aid of navigation, as the flood stages may, and usually do,
obliterate the dredged channels ; but it serves a good purpose while
permanent work is going on.

The permanent work consists of the revetment of banks to
prevent erosion, the closure of side channels or chutes, and the
contraction of width where the river is abnormally wide. The
portion of the bank lying below the low-water line is covered with
a fascine willow mat, about 300 feet wide, and made in lengths of
1000 feet or more. This mat is ballasted with stone and sunk to
the bottom. As it is always covered with water, the willows are
not subject to decay ; but the wire which binds the fascines together
rusts out in the course of time. To remedy this defect, galvanised
and silicon bronze wire is used. After the mat is in place, the
upper bank is graded to a slope of 3 to i by means of a hydraulic
grader, using water jets under a pressure of about no Ibs. per
square inch. The whole surface is then covered with a layer of
stone about a foot thick. In some cases concrete, four inches thick,


is laid on the graded bank with good success. In the lower
sections, where stone is only obtainable by very long hauls, a
substitute is found in artificial stone made of thirteen parts of
gravel and one of Portland cement.

This work on the Lower Mississippi River is carried on under
the direction of a Commission, consisting of four civilian and three
army engineers. The author, who is now a member of the Com-
mission, has been connected with the work for some twenty-five
years, and so writes with personal experience of the problems
involved, and of the methods now in use for the regulation and
control of the great river.

Mr. C. H. Whiting. Mr. W. H. Wheeler, Mr. William Brown,
the Chairman, and Prof. Vernon-Harcourt took part in the Dis-
cussion. The author replied by correspondence.

On the motion nf the Chairman a vote of thanks was accorded
to the author.


Paper by C. H. L. KUHL.


THE European Commission of the Danube has been in charge of
the Lower Danube since 1856. Training works have been executed
at the Sulina mouth, in the Sulina branch, and at the Ismail Chatal.
Besides, the Zeglina shoal, above Galatz, has been dredged.


The navigable depth at zero of the Sulina branch was 8 feet in
1856, 10 feet in 1862, n feet in 1863, 13 feet in 1870, 15 feet n
1886, 1 6 feet in 1889, and 17 feet in 1899. The little M Cutting
was opened in 1869.

Since 1880 eight further cuttings have been opened, and a
ninth cutting is in progress. 21,690,418 cubic yards have been
excavated in these cuttings by three steam dredgers. The different
shoals were treated by the construction of groynes and revetments,
narrowing the upper part of the Sulina branch to 400 feet and the
lower part to 450 and 500 feet. The river has been shortened
by seven nautical miles, and when the last cutting is finished rive
total shortening will be n miles.


The depth of the Sulina entrance in 1856 was from 9 to 7 feet.
The provisional jetties started in April, 1858, were finished in July,
1 86 1, when the depth was 17 J feet. The consolidation of the
jetties in concrete was finished in 1871, when the depth was 19^
feet; this increased to 20 feet in 1872, and to 2o| feet in 1873. This
depth was maintained to 1895 without dredging, with sligb:
reductions only in 1876 and 1879.

The depth of the Sulina entrance being insufficient for modern
requirements in 1894, parallel dams, to reduce the width to 500 teet,
were constructed between the jetties, and a powerful marine hopper
bucket dredger was built.

Dredging was started on the ist October, 1894, increasing the
depth to 22 feet in January, 1895 ; to 23 feet in August, and 24 feet
in September of the same year.


In 1897 the depth was reduced to 23 \ feet from the 6th March
to the iyth April, during a heavy river flood, bringing down much
sediment. Since that time the depth of 24 feet has been main-
tained, the quantity dredged from 1894 to 1899 being 1,790,736
cubic yards.

The practical result of these works is that the size of steamers
navigating the Sulina branch has increased from the maximum of
1462 net reg. tons in 1880 to 2889 net reg. tons in 1900; and for
the port of Sulina the maximum of 2190 net reg. tons in 1892 has
been increased to 3519 net reg. tons in 1900.

M. Vander Vin, Prof. Vernon-Harcourt, Mr. W. H. Hunter, and
the Chairman took part in the Discussion. The author replied
by correspondence.

On the motion of the Chairman a vote of thanks was accorded
to the author.


Paper by W. M. ALSTON.



THE river Clyde rises at about 2000 feet above sea level on the
southern confines of Lanarkshire, and in its course of 102 miles
to Port Glasgow drains about 1400 square miles of country.
Anxious to secure improved communication with the sea, the
magistrates of Glasgow in 1755 consulted John Smeaton, who
found the river obstructed by shoals with from 15 to 24 inches
depth at low water. His recommendation to canalise a portion
of the stream was fortunately discarded, and, under advice by
John Golborne in 1768, contraction by jetties was adopted.

Systematic improvement of the navigation commenced in 1773
by the removal of Dumbuck Ford, the most seaward obstruction.
The deepening of the river was authorised as follows :

In 1770 From Glasgow to Dumbuck Ford, to give 7 feet at high

water, neap tides.
In 1809 From Glasgow to Dumbarton Castle, to give 9 feet at

high water, neap tides.
In 1825 From Glasgow to Port Glasgow, to give 13 feet at high

water, neap tides.
In 1840 From Glasgow to Port Glasgow, to give 17 feet at high

water, neap tides.

By the inauguration of steam navigation in 1812, and the intro-
duction of steam-worked dredgers in 1824, a great impetus was
given to further improvement. Dredged materials generally were
deposited on land, but since the introduction of steam hopper
barges in 1862, almost all material has been carried to sea. The
dredging plant now consists of five dredging machines, one floating
grab, twenty steam hopper barges, a tug, many punts, and two
diving bells. Between 1844 and 1900, 56,591,093 cubic yards
have been dredged from river and clocks. The general result is
that the bed of the river from Glasgow to Dumbuck Ford has
been lowered about 27 feet since 1755, and the bed has been
made practically level from Glasgow to Port Glasgow.

Dredging is now being carried to a depth of 2 2\ feet below
average low water, corresponding with about 33 feet at high water,
with bottom widths ranging from 120 to 500 feet.

The progressive deepening of the river is indicated by the
increasing draught of vessels, thus :


1821. 1831. 1841. 1851. 1861. 1871. 1881. 1801. iqoo
Greatest draught of 1 T i o

vessel in feet ...j 1 ^ *4 '7 18 19 21 22 23 26^

From the Kelvin to Erskine Ferry the river has now the artificial
appearance of a canal, the sides consisting of rough stone slopes
rising to three feet above high water, and the width varying from
365 to 560 feet. Seaward of Erskine Ferry the river widens in
estuary form to two miles breadth at Port Glasgow. The only
remaining training dyke is in the waterway between Dunglass
Castle and Dumbarton Castle. Safe navigation is insured* by
numerous fixed and floating lights, all burning Pintsch's com-
pressed gas, and ordinary buoys and beacons.

\\ith regard to the tidal phenomena of the river, in 1755 springs
rose only i foot 9 inches at Glasgow, and neaps were just sensible.
Springs now rise n feet 4 inches, and neaps about 9 feet.
The low water line has been lowered about 9 feet 7 inches. In
1768 high water was two hours later at Glasgow than at Port
Glasgow, and now the interval is reduced to about one hour

For many years there was a weir above the harbour at Glasgow,
but about twenty years ago it was removed. It is now, however,
in course of being replaced.


Glasgow Harbour embraces the 2 J miles of river between Albert
Bridge and the river Kelvin, and the docks on either side. The
first quay at Glasgow was built about 1662, but by 1792 there was
a length of only 262 yards, at which time 120 yards were added,
bringing the total to 382 yards in the latter year, with a water
area of 4 acres. For many years riverside quays sufficed for all
accommodation. The first dock Kingston Dock was autho-
rised in 1840, but not carried out until 1867. Powers were ob-
tained in 1870 for Queen's Dock, and in 1883 for Prince's Dock;
in 1890 the form of the latter was modified. The latest dock is
that at Clydebank, about six miles below Glasgow, authorised in
1899, and now in course of construction. Although called docks,
these works are tidal basins.

For brevity the harbour and dock accommodation is tabulated
thus :

Glasgow Harbour ...
Kingston Dock
Queen's Dock
Prince's Dock
Go van Passenger Wharf ...
Shieldhall Timber Yard Wharf

Length of Quays.
Lineal yards.
... 6786
... 830
- 3737


Water Area.

I 3 I -75





The graving dock accommodation is as follows :

No. i Dock. No. 2 Dock. No. 3 Dock.

1875. 1886. 1898.

ft. in. ft. in. ft. in.
Length of floor inside face of

caisson ... ... ... 551 o 575 o 880 o

Width of entrance ... ... 72 o 67 o 83 o

Depth on sill at high water,

average springs ... ... 22 10 22 10 26 o

NOTE.- No. 3 Dock is divisable by gates into lengths of 460 and
420 feet.

Fortunately for Glasgow, its trade is most varied : 2686 yards
of quays are devoted to coal and ore, 669 yards to timber,, 175
yards to cattle, 7459 yards to liners, 630 yards for fitting out, and
the remaining 3496 yards to general traders. Where required the
quays are lined with commodious sheds, of one storey, except at
Prince's Dock, where most of them are two storied. There are
no warehouses.

Numerous cranes, ranging in power from 35 cwts. to 130 tons,
are provided. Water mains are laid throughout the harbour and
docks, and the quays are lighted by gas and electricity. The quays
are connected with the railway systems of the country. For cross
river traffic there are four ferries for passengers and two for
passengers and vehicles combined; while for up and down harbour
traffic there is a fleet of small steamers called " Cluthas." Space
does not permit of any description of the quay walls.

The improvement of the river and growth of the city have gone
forward together. When the citizens entered on the task, they
numbered only about 40,000, and the revenue from the navigation
was only ^147; now they number 760,406, and the revenue last
year was ^441,41 9. In 1792 the accommodation consisted of
only 2\ acres of water and 262 yards of quay; now there are 206
acres of water and 15,115 yards of quay. Since 1810, when the
management of the river and harbour was placed under trustees,
down to June, 1900, the capital expenditure has been ^7, 430, 7 02.

In conclusion, the river Clyde is a magnificent example of what
can be done by a public body, without any assistance from

The following members took part in the Discussion : Mr. R. C.
II. Davidson, Mr. William Brodie, Mr. Alexander Gibb, Mr. H.
Home, Mr. W. H. Hunter, Mr. James Brand, Mr. R. Gordon Nicol,
Prof. Vernon-Harcourt, and the Chairman. The author then
replied to their remarks.

On the motion of the Chairman a vote of thanks was accorded
to the author.

The meeting was then adjourned.


Sir JOHN WOLFE BARRY, K.C.B., LL.D., F.R.S., in the Chair.

Paper by D. and C. STEVENSON.


THE lower estuary of the Clyde, which may be called the key to
the upper navigation, and with which this paper deals, is under
the jurisdiction of the Clyde Lighthouses Trustees, the jurisdiction
of the Clyde Navigation Trust ending above Port Glasgow. The
estuary extends from Port Glasgow westwards, the channelway
passing through sandbanks until the " tail of the bank ?? is reached,
below which the estuary is more of the nature of a firth or fiord,
the depth of water varying from 180 feet at Cloch to 370 at the
Cumbrae, although it is deeper at some places, such as opposite
the Cloch, than at places more seaward, such as Skelmorlie. It
is encumbered by several " patches," the highest up being that of
Roseneath, with a depth of 7 feet over it at low water, situated
midway between Fort Matilda and the Roseneath shore. The
depth of the estuary here varies from 60 to 220 feet; and the slope
of the bottom from the tail of the bank is no less than 190 feet in
one mile. The Gareloch, one of the numerous arms of the Clyde
estuary, branches off here; and a little lower down, where the
estuary takes a right-angled bend to the south, Loch Long comes in.
It is navigable for large ships to its head, which forms the
starting point of the projected great Scottish Canal connecting the
Clyde and the Forth by Loch Lomond, which, being only 10 feet
above high water, necessitates little lockage, and has an almost
inexhaustible supply of water. From Loch Long the Clyde
estuary is practically the sea with but few dangers. The Gantock,
lying off Dtmoon, is guarded by a gas-lighted beacon; then another
obstruction, called the Warden Bank, is met with, which, till
recently, was not shown on the Admiralty charts, and was not
generally known to exist. It forms an extension of Lunderston
Bank, and has 34 feet of water over it at dead low water, so that it
does not form a danger to ordinary traffic of the present draught.


Within a few yards of this rocky ledge there is a depth of no less
than 300 feet, so that the west side of the Warden Bank is a
submarine precipice. Skelmorlie Patch is the next shoal, the
boulders coming to within a few feet of the surface. It forms
a danger at present guarded by a gas-lighted buoy and bell. The
estuary south of this to the Little Cumbrae is from 30 to 60 fathoms
in depth, and the navigation through it is unimpeded by dangerous

The Clyde, it will be seen, differs from most of the navigable
rivers of this country in that it does not flow direct into the sea
with the natural accompaniment of a bar, but enters into a deep
and sheltered estuary. The estuary itself is encumbered with
sandbanks, but owing to their sheltered situation they are not
stirred up to any great extent by heavy waves, and the sand is not
carried in to choke up the channelway. There is no " fretting "
of the banks, as in the Mersey, for example. The Clyde Light-
house Trust, which succeeded the Cumbrae Trust in 1871,
immediately took steps to carry out the powers which Parliament
had delegated to them, and appointed Messrs. Stevenson, of Edin-
burgh, their engineers. The improvement of the estuary between
Port Glasgow and the tail of the bank involved, at the same time
as the improvement of the estuary to Glasgow, the conservation of
the entrances to the harbours of Port Glasgow and Greenock.
These harbours required to have the benefits of a navigable fair-
way in close proximity, and yet the channelway for the ordinary
river traffic had to be sufficiently removed from the shore that ships
passing to other ports might be comparatively free from interruption
due to* the local traffic to Port Glasgow and Greenock. The incon-
venient curves round Garvel Point, and the bight at Cartsdyke,
also required to be dealt with and made easier for the passage of
large ships. A channelway, or rather what is really a ship-canal,
has now been formed from Newark Castle (Port Glasgow) to
Prince's Pier, Greenock, having nowhere a less depth than 23 feet
at low water of spring tides, with a minimum width at the bottom
of 300 feet, and slopes of 100 feet on either side, having depths
varying from 20 to 23 feet. Before this canal was begun the ruling
depth at that part of the estuary was 12 feet. The curves at
Garvel and Cartsdyke have been eased by fully one half. These
improvements, great though they are, cannot be taken as final, as
the draught of ships is still on the increase, and perhaps at no
very distant date further deepening and widening of this channel-
way may be called for by the shipping interest. This deep-water
channel has been marked on its northern side by buoys and a
lightship lighted by gas, while the southern side has also been
similarly marked by buoys, and gas-lighted beacons and buoys.
Pilots can, therefore, take vessels through the estuary at night almost


as well as by day; and when fog obscures the lights, the fog signals
at Kempock Point, Fort Matilda, Cloch, Toward, and Cumbrae
give their warning note to the sailor that he is near them.

The removal of wrecks becomes sometimes a serious matter in
such navigations. In the case of the " Auchmountain." lying as
it did in good anchorage ground, the wreck had to be repeatedly-
tackled with explosives, and finally, on the suggestion of our firm,
was covered up by dredgings, which has made the anchorage a
perfectly safe one.

The tidal flow has been greatly facilitated by the dredging works.
causing the tidal flow at Fort Glasgow (where the Clyde
Lighthouses Trustees' works described were executed) down to
Greenock to be more distinctly that of the sea proper than
it was; and especially is this an improvement from a sanitary
point of view, as it renders the admission of fresh water more rapid,
although the actual gain is not so much as might be wished, owing
to the counter effects of the greater amount of sewage to be dealt
with than in former days.

The Chairman, Mr. W. H. Hunter, and Prof. Vernon-Harcourt
took part in the Discussion ; and Mr. C. A. Stevenson replied.

On the motion of the Chairman a vote of thanks was accorded
to the authors.




THE maritime part of the Nervion River, which forms the port of
Bilbao, has a total length of 8f miles, the town being situated in
the upper part. This river has a torrential character, and has
little influence on the navigable depth, which is kept up exclusively
by the tidal waters.

The oldest documents show that this river had a shifting and
shallow bar, and the river itself had sharp curves and many
obstructions, all of which existed to within a few years ago, despite
all the training walls built in past centuries.

The Bilbao Chamber of Commerce, thinking that such conditions
should not continue, obtained from the Government, in 1877, leave
to create a Harbour Improvement Board, with power to levy
certain dues on imports and exports, for defraying the cost of the
works of improvement.

Most excellent results were obtained at the bar by building out
a training jetty 800 metres (2625 feet) in length from the left bank
of the river mouth. Formerly only two feet depth existed at low
tides on the bar; whereas, after building the jetty, a permanent
channel along its whcle length was maintained, with a minimum
depth of 13 feet at low water of spring tides. This enabled
steamers drawing 22 to 24 feet to go in and out at spring tides,
and 18 to 20 feet at neap tides; whereas, before the works were
executed, the maximum draught of steamers was 14 feet at spring
tides and 10 feet at neap tides.

The works executed in the river itself did away with all the
obstructions, and obtained over 14 feet depth at low water of
spring tides up to Bilbao. But as the river mouth is directly
exposed to north-westerly gales, the entrance of steamers continued

Online LibraryInternational Engineering Congress (1901 : GlasgowReport of the proceedings and abstracts of the papers read → online text (page 7 of 37)