A chain boat,John MacGregor (1867). ''The voyage alone in the yawl "Rob Roy": from London to Paris, and back etc.'', London: Maranda merrill, Son and Marston, pp. 97-99. chain tug or chain-ship was a type of

river craft A riverboat is a watercraft designed for inland navigation on lakes, rivers, and artificial waterways. They are generally equipped and outfitted as work boats in one of the carrying trades, for freight or people transport, including luxur ...

, used in the second half of the 19th century and first half of the 20th century on many European rivers, that made use of a steel chain laid along the riverbed for its propulsion.''Kettenschifffahrt'' definition in ''Schifffahrts-Lexikon''
by J. Friedrichson, p. 149. Retrieved 1 Mar 2014.Willi Zimmermann: ''Über Seil und Kettenschiffahrt'', Beiträge zur Rheinkunde 1979, Rheinmuseum Koblenz
digitalized version by Peter Haas
; pdf; 5.9 MB) The chain was engaged using a

steam engine A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be ...

mounted on board and enabled the boat to tow a string of

barge Barge nowadays generally refers to a flat-bottomed inland waterway vessel which does not have its own means of mechanical propulsion. The first modern barges were pulled by tugs, but nowadays most are pushed by pusher boats, or other vessels. ...

s. In

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

, such a boat was variously referred to as a ''Kettenschleppschiff'', ''Kettenschlepper'', ''Kettendampfer'' or ''Kettenschiff'' and in France as a ''toueur''. The chain was raised out of the water over a boom at the bow of the ship and led over the deck along the ship's axis to the chain engine amidships. The transfer of power from the steam engine to the chain was usually achieved using a drum winch. From there the chain was led over the deck to another boom at the

stern The stern is the back or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite the bow, the foremost part of a ship. Or ...

and lowered once more into the river. By moving the stern boom and the two

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally air or water). On an aircraft the rudder is used primarily to counter adve ...

s, front and aft, from side to side it was possible to replace the chain in the centre of the river again, even when negotiating river bends.

History

Chain boat navigation Chain-boat navigation or chain-ship navigation is a little-known chapter in the history of shipping on European rivers. From around the middle of the 19th century, vessels called chain boats were used to haul strings of barges upstream by using ...

revolutionised inland shipping during the

Industrial Revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...

in the second half of the 19th century in Europe and superseded the hitherto commonplace haulage of barges by draught animals or people. The chain drive of these

riverboat A riverboat is a watercraft designed for inland navigation on lakes, rivers, and artificial waterways. They are generally equipped and outfitted as work boats in one of the carrying trades, for freight or people transport, including luxury un ...

s made optimal use of still relatively low-powered steam engines of that period. In addition, the boats were especially well suited to the difficult condition of river navigation that pertained at that time: many rivers were shallow or fast-flowing and effectively precluded the use of

paddle steamer A paddle steamer is a steamship or steamboat powered by a steam engine that drives paddle wheels to propel the craft through the water. In antiquity, paddle wheelers followed the development of poles, oars and sails, where the first uses wer ...

s. As a result, chain boats were soon being used on many rivers across Europe. But by the first half of the 20th century they were increasingly threatened by competition from ever more powerful

s, something that was aided by the canalization of rivers.K. Dietze: ''Chain and Rope Towage on German Rivers.'' In: International marine engineering, Volume 16, New York 1911, pp. 433–439 The first designs and early technical stages in the development of chain boats took place in the mid-19th century, especially in France. The

prototype A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and software programming. A prototype is generally used to ...

of all later chain boats on the rivers

Elbe The Elbe (; cs, Labe ; nds, Ilv or ''Elv''; Upper and dsb, Łobjo) is one of the major rivers of Central Europe. It rises in the Giant Mountains of the northern Czech Republic before traversing much of Bohemia (western half of the Czech Re ...

Neckar The Neckar () is a river in Germany, mainly flowing through the southwestern state of Baden-Württemberg, with a short section through Hesse. The Neckar is a major right tributary of the Rhine. Rising in the Schwarzwald-Baar-Kreis near Schwen ...

and Main was the French

steamboat A steamboat is a boat that is marine propulsion, propelled primarily by marine steam engine, steam power, typically driving propellers or Paddle steamer, paddlewheels. Steamboats sometimes use the ship prefix, prefix designation SS, S.S. or S/S ...

''La Ville de Sens'', which was built by the German engineer, M Dietz, around 1850 in

Bordeaux Bordeaux ( , ; Gascon oc, Bordèu ; eu, Bordele; it, Bordò; es, Burdeos) is a port city on the river Garonne in the Gironde department, Southwestern France. It is the capital of the Nouvelle-Aquitaine region, as well as the prefectu ...

and plied the upper

Seine ) , mouth_location = Le Havre/ Honfleur , mouth_coordinates = , mouth_elevation = , progression = , river_system = Seine basin , basin_size = , tributaries_left = Yonne, Loing, Eure, Risle , tributa ...

between

Paris Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. Si ...

and Montereau. Its technically very advanced operating principle and its engineering features were adopted by all the later European chain steamers.

Design

The hull of these symmetrically-designed boats was almost level with the surface of the water at the bow and stern. This design reduced the power needed to lift the tow chain onto the bow of the boat and also reduced the draught at the bow.Eduard Weiß: ''"Die Kettenschlepper der kgl. bayerischen Kettenschleppschiffahrt auf dem oberen Main"'' in der Zeitschrift des Vereins Deutscher Ingenieure, Vol. 45, 1901, No. 17, pp. 578–584 The greater height of the boat in the centre made it easier to accommodate the steam engine. This deck shape - low at the bow and stern, and higher in the centre - is typical of all subsequently built chain boats. Chain boats were favoured on shallow rivers with fast currents. This was the reason for the flat, shallow draught of their keels. Chain boats optimized for particularly shallow water had a draught of only when unladen. Even fully laden with coal, their draught was only about . This shallow draught enabled river transportation even in the dry summer months when the water level of rivers could be very low. Shorter chain boats - with lengths from , and widths from - were more manoeuvrable and well suited to narrow rivers with many bends, for example on the

Saale The Saale (), also known as the Saxon Saale (german: Sächsische Saale) and Thuringian Saale (german: Thüringische Saale), is a river in Germany and a left-bank tributary of the Elbe. It is not to be confused with the smaller Franconian Saal ...

. Longer craft - with lengths from , and widths from - were more suited to relatively deep rivers such as the Elbe. The deeper a waterway was, the greater the power needed to lift the heavy chain. The bow of the ship was pulled down further. On larger boats this effect is less.''Zeitschrift für Bauwesen'' Volume 16, Berlin 1864, p. 300, Verein für Eisenbahnkunde zu Berlin, Protokoll vom 10. November 1863
digitalized version
The hull itself was made of iron or wood and could withstand light impacts with the riverbed. If, however, it was holed the hull was compartmentalized internally by several waterproof bulkheads that prevented the craft from sinking. Below deck were the steam engine, the coal bunkers and the crew accommodation. Kettenschiff Schematische Darstellung des Kettenverlaufs

Kettenschiff Schematische Darstellung des Kettenverlaufs

Control and navigation

In chain boat navigation the chain was simply laid "loose" on the riverbed for long distances of up to several hundred kilometres. Only the deadweight of the massive chain, which weighed about or , and its natural snagging on the sand and stones of the riverbed provided resistance, so that the chain boat and its attached barges could haul themselves along the chain. The water bore the weight of the boats and barges, whilst the chain only had to cope with the power of the engine. The chain was only anchored at its two ends so that boats could continue to haul themselves to the end of the chain route. A problem was caused by sideways displacement of the chain. At bends in the river there was a tendency for the chain, that was laid in a curve, to increasingly pull itself straight and so move towards the inside of the bend. In order to prevent this, chain boats were fitted, fore and aft, with large, powerful rudders. These rudders sometimes had a length of over four metres and were worked with the aid of control wheels on the deck. At the bow and stern of the boat the chain was led along a boom that projected well beyond the end of the deck. This prevented the chain from hitting the long rudders. The booms were movable and could be swung sideways using a hand crank. The boat could thereby be oriented at an angle to the direction of the chain. This also improved the chances of replacing the chain back in the centre of the river. The boom was also fitted with chain interception equipment so that, in the event of the chain breaking, it would not be able to run away. If the chain catch was not quick enough to hook into the chain, it would simply run away and disappear into the river. It then had to be painstakingly located with a drag anchor and salvaged.Otto Berninger: "Die Kettenschiffahrt auf dem Main" in the Main Shipping Reports of the Society for the Promotion of the Wörth am Main Shipping and Shipbuilding Museum, News Sheet No. 6, April 1987, 111 pages.

Chain driver

In the first generation of chain boats the chain ran over chain drums at the side of the boat. In fast-flowing currents or when there were problems lifting the chain due to silting or obstacles on the riverbed such as large rocks, the boat could swing off-course markedly and list to one side. As a result, on later chain boats, the chain drive was always located on the centerline of the boat.

Drum winch

The older chain boats on the Elbe, the chain steamers on the Neckar and the three craft on the Main belonging to the Hessian ''Mainkette'' company used a drum winch to transfer power. In order to ensure the necessary traction on the chain on the driving drums, the chain was wound several times around two traction drums placed one behind the other in the centre of the boat. The chain ran in four to five grooves and was alternately wound over the front and rear drums. The disadvantage of this method was that the chain frequently broke. This did not simply occur due to the overloading of the chain by the length of the barge train. It has been calculated that even if the chain links wore down to half their original cross-section, this force would not have led to a break. Rather the problem lay in the fact that frictional wear on the forward traction drum was much heavier than on the rear. And once the diameters of the two drums became unequal, more chain wrapped around the after drum than could be handled by the forward one. This could produce tensions both on the drums and between them that were so large that the chain links could not withstand the tensile load and their fracture limit was exceeded. – 2. Auflage 1904–1920 This effect became even more pronounced if the chain became twisted, ''e.g.'', the chain was pulled to one side or had even formed knots. This increased the turn radius by up to 25%, whereby the 5% elastic limit of the chain was reached. The transfer of tractive force from the drums to the chain was only achieved by friction. If frost or ice built up, the chain could slip. In such events, hot water was poured over the drums. Another problem with drum winches was the relatively large length of chain – – that had to be wound several times around the two drums. If the chain boat was only used to haul barges upstream, it could not simply reduce the amount of chain needed for the drums on the way back otherwise, after a certain time, the surplus chain would pile up at the head of the operating section and there would be no slack at the start. In order to try to avoid this problem, the chain boat always carried the corresponding section of chain with it downstream and dropped it at the start of the chain route.A. Schromm: ''Kettenschifffahrt und Elektricität''. In: Zeitschrift für Elektrotechnik, Jahrgang 13, Vienna, 1895, pp. 264–266, onlin
Internet Archive
/ref> As a result, there was a continual movement of the chain, that made control more difficult in more dangerous sections of the river, such as

rapids Rapids are sections of a river where the river bed has a relatively steep gradient, causing an increase in water velocity and turbulence. Rapids are hydrological features between a ''run'' (a smoothly flowing part of a stream) and a ''cascade' ...

. In particular, reinforced chain sections that were deliberately used, moved continually upstream. Also jettisoning the chain temporarily when two chain boats met was relatively difficult due to the multiple windings of the chain round the two drums. Many of the chain steamers without their own auxiliary engines had different gearing for moving upstream and downstream. When travelling upstream, it was designed for higher traction; when travelling downstream it was engineered for faster speed.Sigbert Zesewitz, Helmut Düntzsch, Theodor Grötschel: ''Kettenschiffahrt''. VEB Verlag Technik, Berlin, 1987,

Chain grip-wheel

The chain grip-wheel (''Kettengreifrad'') was designed in May 1892 by Ewald Bellingrath, the director general of the German Elbe shipping company, ''Kette'', in Übigau, in order to overcome the problem of continual chain breakages. This device was used in various chain ships on the Elbe as well as the eight chain boats of the Royal Bavarian Chain Boat Company on the River Main. The idea of the mechanism was to use just one drum or wheel for the actual drive and not to wrap the chain around it several times, but to wind it only partially over the wheel (Diagram 1). The design was supposed to engage the chain securely without letting it slip. It was also supposed to work with different chain thicknesses and lengths of chain link, and independently of their orientation (e.g. angled or on their side). Even if a knot formed in the chain the design was supposed to respond without a problem. The chain was engaged in the transmission area by many movable side pins that hooked the chain from the left and right hand sides (Diagram 2). Critics were initially concerned that the many individual moving components of the "catcher" would quickly wear. This fear was allayed, however, by a three-year-long trial that began in May 1892. On the contrary, by using a catcher, the transmission of power was improved so that more barges could be hauled in one string. As a consequence all new chain boats built by ''Kette'' in Übigau were fitted with catchers. On the River Main, however, the chain grip-wheels were replaced by drum winches again in 1924, because the first ones were too prone to failure. Antrieb Kettenschiff Kettengreifrad 2

Electromagnetic drum

Another attempt to reduce the frequency of chain breakages and the movement of the chain in the river came from France and was introduced in November 1892 on the Lower

near

. Its inventor, ''de Bovet'', developed a technique to increase the friction on the transmission drum by magnetic force. Here, too, the chain was only wound three-quarters of the way around the traction drum. The engagement of the chain on the traction drum was achieved by magnetic force created by

electromagnet An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into a coil. A current through the wire creates a magnetic field which is concentrated in ...

s that were built into it. The electric current needed for this was generated by its own engine and a ca. 3 HP

dynamo "Dynamo Electric Machine" (end view, partly section, ) A dynamo is an electrical generator that creates direct current using a commutator. Dynamos were the first electrical generators capable of delivering power for industry, and the foundati ...

. The magnetic force was sufficient, despite the short length for which the chain was wrapped around the drum, on a trial with an old, chain to generate a tractive force of around .

Auxiliary engines

In addition to the main engine for hauling the chain, most of the later chain boats had an auxiliary engine. This enabled boats to be driven without needing to use the chain, and was mainly used when travelling downstream. Downstream journey times were thus reduced because of the higher boat speeds that could be attained and because it was no longer necessary to follow the time-consuming and complicated passing procedure when boats travelling in opposite directions on the same chain encountered one another. In addition, it spared wear and tear on the chain.

Water turbines

In 1892 chain boats using ''Zeuner''

water turbines A water turbine is a rotary machine that converts kinetic energy and potential energy of water into mechanical work. Water turbines were developed in the 19th century and were widely used for industrial power prior to electrical grids. Now, th ...

were introduced on the Elbe. They were a precursor of the present-day hydrojet propulsion systems. In addition to faster downstream travel times, the auxiliary engine also enabled steering corrections during chain operations and simplified turning manoeuvres. Water turbines were used on several chain boats on the Elbe and on the

Bavaria Bavaria ( ; ), officially the Free State of Bavaria (german: Freistaat Bayern, link=no ), is a state in the south-east of Germany. With an area of , Bavaria is the largest German state by land area, comprising roughly a fifth of the total l ...

n chain boats on the Main. Water was sucked in through two rectangular intakes in the side of the chain steamer's hull. It then flowed through the turbine inside the hull. The turbine accelerated the water and forced it through the rear-facing outlets in the side of the hull. The outflowing jets of water propelled the boat forwards (upper diagram of the elevation view). To reverse the direction of travel, the reversing element was swung around so that water was forced in the opposite direction (lower diagram of the elevation view). The pump direction of the turbine was always the same, regardless.K. Dietze: ''Chain and Rope Towage on German Rivers.'' In: International marine engineering, Volume 16, New York 1911, pp. 498–502''Schiffsantrieb mittels der Marchand'schen Doppelturbine''
at dingler.culture.hu-berlin.de. Retrieved 4 Mar 2014. These second generation chain steamers were equipped with two of these water turbines, which were found on the

port A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as H ...

and

starboard Port and starboard are nautical terms for watercraft and aircraft, referring respectively to the left and right sides of the vessel, when aboard and facing the bow (front). Vessels with bilateral symmetry have left and right halves which ar ...

sides. During a turning manoeuvre the water flowed forwards on one side and backwards on the other in order to rotate the boat.

Paddle wheels and screw propellers

On the Danube, chain ships were unable to travel downstream on the chain because of strong currents. If the chain boat was forced to stop suddenly, for example as a result of a chain breakage, there was a real danger that the barges at the rear would run into those at the front, causing a shipping accident.Georg Schanz: "Studien über die bay. Wasserstraßen Band 1, ''Die Kettenschleppschiffahrt auf dem Main''", C.C. Buchner Verlag, Bamberg, 1893, pp. 1–7 –
digitalized version
by Digitalis, Library for Economic and Social History, Cologne, retrieved 29 October 2009 They therefore had large, side-mounted

paddle wheel A paddle wheel is a form of waterwheel or impeller in which a number of paddles are set around the periphery of the wheel. It has several uses, of which some are: * Very low-lift water pumping, such as flooding paddy fields at no more than a ...

s as auxiliary propulsion for the downstream journey which were driven by engines with a rating of 300–400 hp. The third type of auxiliary propulsion was the

screw propeller A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upo ...

.Carl Victor Suppán: ''Wasserstrassen und Binnenschiffahrt''. A. Troschel: Berlin-Grunewald 1902 ''Vor- und Nachtheile der Tauerei''. pp. 266–269 This type of auxiliary system was used by some craft on the Danube for downstream journeys in order to enable barges to be towed in that direction as well.

References

Literature

* Sigbert Zesewitz, Helmut Düntzsch, Theodor Grötschel: ''Kettenschiffahrt''. VEB Verlag Technik, Berlin, 1987, * ''Kettenschleppschiffahrt''. In: Otto Lueger: ''Lexikon der gesamten Technik und ihrer Hilfswissenschaften'', Vol. 5, 2nd completed revised edition, Deutsche Verlagsanstalt: Stuttgart und Leipzig, 1907, pp. 460–46
zeno.org
* Georg Schanz: "Studien über die bay. Wasserstraßen Band 1, Die Kettenschleppschiffahrt auf dem Main", C.C. Buchner Verlag, Bamberg, 1893

* Theodor Grötschel und Helmut Düntzsch: ''Betriebsmittelverzeichnis der KETTE – Deutsche Elbschiffahrts-Gesellschaft''. In: Ewald Bellingrath: ''Ein Leben für die Schiffahrt'', Schriften des Vereins zur Förderung des Lauenburger Elbschiffahrtsmuseums e.V., Vol. 4, Lauenburg, 2003 * Carl Victor Suppán: ''Wasserstrassen und Binnenschiffahrt''. A. Troschel: Berlin-Grunewald, 1902, Section: ''Dampfschiffahrt''. (''Ketten- und Seiltauer''. pp. 261/262, ''Tauereibetrieb''. pp. 262–265, ''Auf- und Abnehmen der Kette''. p. 265, ''Kettenrolle mit Fingerlingen''. p. 266, ''Elektrische Kettenrolle''. p. 266, ''Vor- und Nachtheile der Tauerei''. pp. 266–269, ''Versuche mittels endloser Kette''. pp. 269/270)

External links

Video of a journey on an electric chain boat through the Tunnel of Riqueval
retrieved 15 November 2010
Forum with many old photographs of chain boats from France
(French), retrieved 12 July 2013 {{ModernMerchantShipTypes Shipping Barges