Classes of Ships
Liners | Intermediate Liners | Cargo Liners | Tramps | Tankers | Cable Ships | Fruit Carriers | Cross-Channel Packets and Coastal Liners | Pleasure Craft | Train Ferries and Motor Car Ferries | Tugs and Salvage Craft | Dredgers | Harbour Craft
The term Liner originally meant a ship which was employed upon a regular route or line as distinct from the “ Tramp *’ which went all over the world and picked up a cargo wherever there was one to be had; to-day many ships are taken off their regular routes in order to go on pleasure cruises and some large ships are regularly employed on cruises and nothing else, but they can scarcely be classed as other than liners. The word has lost something of its original meaning and applies to any luxurious or large passenger carrier.
The passenger or mail liner is usually of considerable size and speed and can be easily recognized by her large number of passenger decks rising above the upper deck.
More and more of these passenger promenade decks are being enclosed by glass windows and the superstructure is generally very much heavier in appearance than was formerly the case.
The giant express liners of the Western Ocean are in a class entirely by themselves, both on account of their high speed and the extreme luxury of their internal decorations.
The term liner is usually taken to refer to vessels having a service speed in excess of sixteen and a half knots.
The greatest proportion of the passenger traffic of the world is carried on by intermediate liners, that is to say by ships which do not go much above 20,000 tons and which are less speedy than the larger type. Such ships are usually very much more comfortable and they often combine passenger carrying with large cargo capacity. The liners on the New Zealand service have very large refrigerated space, and a cargo deadweight of 13,000 tons is by no means uncommon in these inter* mediates. Japan has concentrated very largely on this class of ship and a Japanese liner of round about 10,000 tons gross compares very favorably in comfort and service to the largest of the fast liner group.
The cargo liner is encroaching more and more on the spheres of the general trader or tramp ship; generally speaking, a cargo ship may be distinguished from a passenger liner by the absence of decks above the upper deck and by her thicker masts and larger number of heavy cargo derricks and derrick posts.
The modern cargo liner may have a speed of fourteen knots or even more, and she very often carries passengers in considerable comfort, but no cargo ship may carry more than twelve without a special license and then she encroaches on the intermediate liner.
Some of the best cargo liners have accommodation for their officers and crew all amidships, above the upper deck, and they often look like passenger ships in consequence; such ships are the Beaver class of the Canadian Pacific and the motor ships of Furness Withy.
Among the cargo liner class are ships entirely built for the carriage of frozen or chilled meat, such as the well-known ships of the Blue Star Line, which may have up to 700,000 cubic feet of insulated or refrigerated space.
There are many other ships built for specialized trades such as for the carriage of newsprint paper rolls or cement.
British maritime supremacy was built up almost exclusively by the tramp ship, sometimes poetically described as a “ sea gipsy,’* and it is this type which has suffered most severely by the great decline in international trade and by the competition of the cargo liner.
A tramp is a ship which can be chartered by a merchant in any part of the world and which in consequence does not trade on any regularly defined route. Some are specialized to the extent that they are especially suitable for the transport of grain or coal or some other commodity, but by far the largest proportion used to leave British ports with coal and return with whatever they could pick up, but in these hard times, with the demand for British coal falling off, they all too often leave these shores empty.
The tramp or general trader remains the backbone of Britain’s seaborne traffic and it will go hard with us if their number is insufficient to meet our needs in the event of future hostilities. Drab in appearance and not often exceeding twelve knots, the tramp has a difficult future, but modem improvements have produced several types of “ Economy” ships which should go far to enable us to hold our own.
The tanker deserves a special mention, because her place is becoming more and more important accordingly as the world becomes more and more dependent upon some form of oil for its industries.
The British Empire is in an awkward position, because with her Royal Navy, Royal Air Force and mechanized Army dependent for the most part upon oil, and with over one third of her mercantile vessels driven by oil engines or burning oil in steam boilers, she is particularly dependent upon foreign good-will; very little oil is in the British Empire and our principal supplies, from Iran, are in a dangerous quarter of the world.
In the old days, oil was carried in barrels and it was thought that steamers were far too dangerous to undertake the carriage of oil because of dangers of fire, so it was not until 1886 that the first practical tanker was built; she was the Gluckauf, a small vessel of about nine and a half knots speed.
The modem tanker is easily recognized as her engines are usually right aft and she looks very long and sits low in the water when fully loaded, earning the title of the “ Dachshund of the seas ” in consequence.
Discipline in a tanker is rigid on account of danger from fire, and the dangerous time is when she has been emptied and her holds still give off inflammable vapor.
They are rigidly constructed, usually on the Isherwood longitudinal system described elsewhere, and special precautions, in addition to bulkheads, are taken to prevent any possible leakage of the petroleum into the engine-room or boiler spaces, petroleum being capable of leaking through where water cannot.
Most tankers have accommodation for a few passengers and they are very comfortable. The steel decks are encumbered by a large number of hatch covers and in order to provide access above deck from one end of the ship to the other very narrow “ Flying bridges ” are provided.
Another specialist is the cable-laying ship, but in days gone by it used to be the opinion that any ship that was large enough could do the work.
The Great Eastern performed her only really useful work in laying cable, but since then the type has become more and more specialized.
In appearance the ships look like small passenger ships and are usually white* painted, but the outstanding vessel and the largest in the world is the Dominia, belonging to the Telegraph Construction and Maintenance Company, which may often be seen at her moorings near Greenwich pier on London river.
This splendid vessel has fine lines like a passenger liner, she has one graceful yellow funnel and four tall masts and is close on 10,000 tons in measurement; in common with all cable layers she can be distinguished by her sheaves or leads for laying out the cable over the bows.
She has four cable tanks, each about fifty feet round and about twenty-seven feet high and each is a reservoir for 1,000 miles of cable, coiled beneath the surface of the cooling water in the tanks, and from stem to stem she is a museum of scientific ingenuity.
During hostilities all cable ships rank as warships and are therefore liable to attack without warning.
In all shallow waters and for all short lengths of cable, it is paid out over the bows on the weather side of the layer.
Sometimes cable weighing more than 10,000 tons is carried in the tanks.
No less wonderful are the grappling appliances for fishing the cable from the ocean bed to repair damages or to remedy defects, and frequently it has to be raised from 1,500 fathoms or more.
The cable must be laid so that it just rests comfortably on the ocean bed; it must not be taut so as to cause a strain, but on the other hand it must not hang in large festoons between the peaks of mountain ranges beneath the sea.
A cable-vessel by day, when engaged in repairing or laying telegraph cables and when not under command in consequence, exhibits two red circular shapes with a white diamond between, arranged vertically. By night, two red and one white ight take their place, and if the ship is not under way, no side lights are shown.
The fruit-carrying vessel usually has beautiful lines and is almost invariably painted very light grey or white.
She usually has accommodation for a limited number of first-class passengers and the fruit is stored in the “ tween decks.”
Elders and FyfFes have done much to introduce the banana as a food item in this country and each of their vessels carries anything up to 100,000 stems of them at a time.
Cross-Channel Packets and Coastal Liners
The modem passenger-carrying ships round the British coasts are in every respect smaller editions of the large ocean liner.
In appearance they look the same except for their size and internally they are very comfortable and well appointed.
The cross-channel ships have fine lines on account of their high speed and it is these fine lines which make them lively in a seaway, particularly as nearly all the stretches of water covered by them have the reputation of providing nasty lumpy seas.
The paddle-steamer remained until quite recently on these cross-channel runs, because the paddle wheels undoubtedly made them steadier, and it was not until a few years ago that the last pair, run by the Zeeland Steamship Company between Flushing and Folkestone, was withdrawn.
Some weird contraptions were introduced last century, such as double-hulled craft, that is to say the superstructures were built across two hulls side by side, but they were not very successful and must best be regarded as freakish experiments. The first turbine ship on the cross-channel service was the South Eastern and Chatham Hallway Company’s The Queen early in this century, and thenceforth, developments were rapid.
Still among the packet class, but more approximating in build to the coasting ship, is the slower type exemplified by the three motor vessels of the Belfast Steamship Company.
A class of ship easily recognised, is the coastal pleasure or excursion steamer, because she is usually a “ paddler ” and she is always of light looking build with fine graceful lines, more often than not with one mast only.
The paddle-steamer is very fascinating to watch, she is easy to handle, is steadier because of the extra width provided by the paddle boxes and she is of very shallow draught; fortunately there is no indication that her sphere of usefulness is at an end, in fact modem developments have been incorporated into the design of recent ships of this type, such as the diesel-electric drive.
Curiously enough, however, a series of paddle ships built during the last few years has been designed so that broadside on, except for the chumed-up water amidships, they would look like ordinary screw ships and this seems a pity.
The idea that excursion paddlers are only lightly constructed and unable to stand up to heavy weather is quite a mistaken one and it was Lord Jellicoe who proved their inestimable worth by taking most of them over for mine-sweeping and patrol work during the Great War. Their shallow draught enabled them to cross most mine-fields in safety and when, later on in the war, it was necessary to build minesweepers, they were largely of the paddle type.
On the Clyde, the turbine-driven excursion steamer is a very fine type and it was from experience gained by an early Clyde ship that The Queen, mentioned above, was evolved for cross-channel work.
Train Ferries and Motor Car Ferries
Train-ferries can easily be recognised because they almost invariably have very thin fiat-sided funnels, set side by side but widely spaced, one on either beam.
They have open stems which may possibly be closed by doors, and railway tracks running the entire length of the vessel.
The principal advantage of the train-ferry is that the time and labour of loading and unloading cargo or passengers is saved, because the vessel just backs against a specially constructed stage at the terminal point, so that the rails on the deck of the ship fit with the rails on the quay, and the tram is run in.
They are particularly of value for short crossings and show to best advantage in smooth water because their unusual construction makes them most uncomfortable in other circumstances. We had not favoured them much in this country until the war, when three train- ferries were constructed especially to run from the war-time port of Riohborough, near Sandwich, across to the other side of the channel; these steamers are to-day run by the London and North Eastern Railway between Harwich and Zeebrugge.
Shortly there will be another train-ferry service in operation, that between Dover and Dunkirk, and special docks have been constructed at Dover to facilitate the handling of these craft; difficulties have been encountered owing to the great difference in height between high and low water and to unexpected engineering hitches.
These Dover ferries will have large garage accommodation for passengers* cars in addition to the trains.
There are one or two cross-channel vessels designed and run purely as motor-car ferries and the cars run straight on in the same way as the trains do in the larger train-ferries.
The weather to which all the cross-channel craft are subjected is heavy, especially in winter months, and the strain on ship and navigators is tremendous; the ship has to be fine-lined for speed and yet staunch enough to face heavy seas and much buffeting in getting into ports in all weathers; day and night in all seasons the routes are maintained and the strain on the crew of continually cutting right across the shipping lanes is tremendous.
Travellers often complain of the discomforts of a cross-channel journey; let them think a bit of the men who face all weathers and who just carry on, or let them stand on the Admiralty Pier at Dover, under cover at the shoreward end with the seas breaking right over the roof, and let them watch a cross-channel packet fighting her way in or out of the harbour; perhaps they will live to marvel and to complain less.
Tugs and Salvage Craft
Some of the most attractive and ubiquitous craft of all are tugs; they are picturesque and there can be few people who have not seen some form or another of tugboat. The large deep-sea tugs are quite large ships and some of those on the lower reaches of British rivers are by no means small.
The Dutch have always specialised in powerful tugs for deep-sea towing, and have many famous feats to their credit, such as pulling large floating docks half across the world. They always give the impression of great power, an effect enhanced by the fact that most of them have their funnels and bridge pushed forward, and they more often than not have a characteristic stem, in which the bulwarks aft have a very strong “ tumble home,” a characteristic originating from the river tugs employed on lighterage work to enable the lighters to push their sloping stems right up over the tug’s stem and so keep station without difficulty.
The power of a modem tug is very great and the amount of space occupied by their engines can be judged by the very slight difference between the gross tonnage total cubic capacity of the ship, and the net tonnage, or what is left after deducting OBgine and boiler spaces. Towing is an extremely difficult business and the skippers of tugs are some of 8fco finest seamen afloat; to watch a river tug being handled, spinning round on her own length, or towing lighters lashed abreast, is an education in itself.
In the days of sail, London tugs often went as far afield as Dungeness and even well beyond the Scillies in order to wait for an incoming ship.
To watch tugs assisting a giant Western Ocean liner into her berth is another interesting sight and on the other side of the Atlantic they push with their noses against the liner’s side.
At night, a vessel towing, exhibits, in addition to her sidelights, two white lights an her foremast not less than six feet apart and if the length of the tow is more than 900 feet, a third white light above or below the others.
Many tugs are also fitted with salvage appliances, such as powerful pumps and oxy-acetylene gear, and again there are craft specially designed as salvage ships and which, although as capable of handling heavy tows as the ordinary tug, do not undertake ordinary towage duties except in conjunction with salvage operations.
There are some very powerful German sbips of this class and some very fine work they have done.
Most of these salvage craft are based on regular ports, such as at Queenstown, Gibraltar, Aden, and so on.
Some of the most powerful tugs round the British coasts are the Dover Harbour twin-funnelled vessels, and the Lady Brassey is well known for her services up and down the channel.
On long tows the hawser usually consists of part wire and part hemp, the wire length is easier to pay out or shorten as necessary and is much easier to slip in an emergency, while the hemp allows the necessary elasticity and prevents anything carrying away; the wire will probably be about four and a half inches in girth and the hemp twelve inches, the two combined giving a length of anything up to 150 fathoms. To decide upon the length of the tow-rope is a matter demanding much experience and good judgment, but as a general rule, the more sea-room that there is, the longer the tow, and, certainly in bad weather, the longer the tow the greater the safety.
Tugs also sometimes serve as tenders to disembark passengers from ships which lie out in open roadsteads, but they naturally have to be certified for this purpose.
The histories of many of our tug-owning companies make extremely interesting reading and many have roots well into the past; Turner's picture of the Fighting Temeraire has immortalised one of the tugs of William Watkins, which is shown pulling the old ship to her last resting-place.
It does not require much stretch of the imagination to realise the difficulties of effecting a satisfactory tow even in calm waters, especially of such a thing as a giant floating dock which is quite powerless to help herself and which cannot be steered, or of a ship whose engines are not functioning, but in heavy weather the difficulties and dangers are tremendous.
In the first place getting a hawser across to the other vessel is a difficult operation, but when the two vessels are plunging wildly in seas running mountains high, the difficulties are increased and once having passed a hawser the next thing is to wait for it to part and to wonder how long it is going to be before the whole business has to be done all over again. The tow is one minute riding high above the stem of the tug, threatening to plunge down and crush it, and the very next minute it may be entirely lost to view, hidden by a wave crest or dipping in the heavy swell.
Akin to the salvage tug are the vessels employed by Trinity House or Harbour Commissioners for raising and lowering buoys, removing wrecks and visiting light-vessels, towing them home for repairs, if necessary, and generally supervising all beacons and coastal marks.
How anyone can work up an affection for a dredger is beyond most men’s comprehension and yet the crew of these extraordinary craft profess to do so, but perhaps it is perverted; on the other hand, ugly and dirty as they are externally, they are certainly most wonderful creations. Nearly all ports have dredgers and with the increasing draught of modem ships their duties are increasing; channels have to be maintained at a given depth and in a port such as London, which stretches for forty miles or more, the work is unceasing.
The class includes a very large number of types, differing according to the work upon which they are engaged. Some are towed to their station by tugs and others are self-propelled.
The chief type in use in British ports is the bucket dredger, which has a large number of buckets attached to an endless chain working on a ladder which can be raised or lowered as required.
Having scooped up the mud from the bottom, the buckets tip’their spoils out as they go over the top of the wheel to which the chain is attached, and this either goes into the dredger's hold or more often nowadays down chutes into barges alongside. A bucket dredger such as is in use in the Thames Estuary dredges about 2,000 tons of spoil hourly.
To hear one at work is to gain an impression of a soul in torment; the noise is unearthly, not necessarily because of its volume but because of its weird, wheezing coughing and squeaking which is like nothing heard elsewhere; people have often been kept awake at night in seaside hotels under the impression that the place was haunted, and no wonder.
The type which carries her own spoil is called a hopper dredger and when she gets to a place sufficiently far out at sea, the bottom is opened, the spoil dumped and the water pressure immediately closes the traps in the bottom again, and this is where the skill in design and construction comes in, because it is a tremendous strain on the dredger to be suddenly relieved of several thousand tons weight of sand or rock.
If barges convey the stuff to sea instead of the dredger they are called hopper barges and these similarly may be either self-propelled or dependent on tugs for their movement.
Sometimes the bed of the river or channel may be of rock and the dredger has p, large grab or crane which picks up a large chunk at a time and deposits it in a place of safety, or the buckets may have large teeth which serve the same purpose.
Others are suction dredgers, such as those well known on the Mersey, and one owned by the Mersey Docks and Harbour Board is nearly 500 feet in length and she can handle 10,000 tons of sand in fifty minutes.
As its name implies, the suction dredger sucks up the liquid mud through pipes, perhaps over three feet in diameter and the pumps of the above mentioned vessel are effective up to depths of 70 feet.
British built dredgers are about the finest obtainable and they are found all over the world. Others again are used for making canals and they usually have long overhanging bows so that they can be moored close up to the bank which they proceed to eat away.
In the daytime a dredger at work hoists two black balls and a red flag in the form of a triangle, the flag indicating the side on which it is dangerous for other vessels to pass; at night two white and one red lights take their place, and if it is safe to pass on either side, three white lights are used.
Other floating wonders likely to be met with in a port are Grain Elevators mod Coal Elevators, which are sometimes self-propelled aiid which do away with the necessity of ships having to wait for a berth; the former suck the grain out of the ship’s hold by long pipes and the latter bunker a steamer from barges to lighters alongside, and the speed with which they work is astounding.
8uch methods save all the time of warping in and out of dock or they are frequently hi aw in very congested waterways when there is no vacant space alongside the quay.
Floating cranes, again either self-propelling or otherwise, are interesting and frequent sights in large ports.
In busy waterways ferries are continuously in operation and they usually have rodders at both bow and stem to facilitate manoeuvring; the Mersey ferries are very fine craft capable of accommodating about 2,000 people each. The Woolwich Free Ferry is conducted by quaint-looking paddle craft with a very tall, thin, bell- topped funnel at either end: carts and cars are carried on the upper deck and passengers below.
In all weathers, fine and foul, these services are carried on, and very rarely indeed does fog interrupt them, and the work must be trying and exacting.
A thousand and one other craft of all shapes and sizes could be mentioned, foreign as well as British, but probably those most likely to be met with have been described.
Source: Talbot-Booth, Pay-Lt. E. C., R.N.R., Ed., Ships and the Sea: A Cruising Companion, Sampson Low, Marston & Co., Ltd., London, First Edition, u.d. c1935, Chapter XV Classes of Ships, P. 207-221.