Defence was required not only on all entrenched fronts but also at home and sea; both for reasons of reconnaissance and fighting. There were many advances in existing methods of defence, as well as new inventions. We have focused on a few, not only pertinent to engineering but also to the conflict and future warfare.

Paravanes

Paravanes were developed 1914-1916 by Lieutenant Burney and Commander Usborne as a direct result of the War, due to the need to destroy oceanic mines. The paravane would be strung out and streamed alongside a towing ship, normally from the bow. The wings of the paravane would tend to force the body away from the towing ship, placing a lateral tension on the towing wire. If the tow cable snagged the cable anchoring a mine then the anchoring cable would be cut, allowing the mine to float to the surface where it could be destroyed by gunfire. If the anchor cable would not part, the mine and the paravane would be brought together and the mine would explode harmlessly against the paravane. The cable could then be retrieved and a replacement paravane fitted. The method was still in use in the Second World War.

Burney developed explosive paravanes as an anti-submarine weapon or a 'high-speed sweep'. It was a paravane, containing 80 pounds (36kg) of TNT towed by an armoured electric cable. The warhead was fired automatically as soon as the submarine touched the paravane or towing cable, or by hand from the ship's bridge. It could be quickly deployed into the water, could be towed up to 25 knots (29mph), and recovery if unsuccessful was reasonably simple.

Mines were used extensively to defend coastlines, shipping, ports and naval bases across the world. The Germans laid mines in shipping lanes to sink merchant and naval vessels serving the Allies, this meant the destruction of vital supplies such as food as well as the lives of seamen. Indeed, psychologically they were powerful weapons, even if not present they raised the fear that they may be. Technically, mining was limited by treaty to areas within three miles of an enemy’s coastline, so as not to endanger neutral ships. However, both sides quickly came to ignore this agreement, and the North Sea became a place of immense danger. This also impacted the neutral countries of Norway and Sweden, which depended heavily on the North Sea for commerce, as the British North Sea coast and areas around ports in the Low Countries were particularly heavily mined. This meant that ships could not move freely. Methods for clearing were also vital to the Royal Navy whose freedom was being limited; mines severely restricted the free manoeuvring of forces. Paravanes were a new weapon in the battle to secure both military and civilian shipping, part of the reason why small vessels were normally used to drag them was because they were more manoeuvrable than larger boats. As one machine was pitted one against the other it was also a relatively safe way of clearing mines.

Mines were also used by the Allies for example; the Royal Navy and the United States Navy laid a huge minefield from the Orkneys to Norway to combat German submarines: from June to October 1918 almost 70,000 mines were laid spanning the North Sea's northern exits; after the war it took 82 ships five months to clear them.

Crossing a ditch

Crossing a ditch

by User Not Found | 19 May, 2014
The design drawings show how different forms of the weapon were developed and tested, allowing their suitability for a given situation to be tested: although normally from the bow the drawings also show starboard models.
Airships

Whilst the British army had favoured the production of aeroplanes over airships before the war, the threat posed by the use of airships by the Italian and German armies pushed the development of both rigid and non-rigid airships. The German Zeppelin and Schütte-Lanz were causing civilian and infrastructure casualties, bringing the war to mainland UK. They also worked as a remarkably strong propaganda tool and became a symbol of fear. The British needed to catch up; the Germans had invested heavily in training and design development and were far ahead of Britain in capability. The onslaught of German submarines against the Fleet also pushed airship construction along.

In 1916 Short Brothers were awarded a contract to build two large rigid airships for the Admiralty (airships were originally conceived as naval escorts). Short chose a site at Cardington, about two miles south-east of Bedford. With its existing light engineering industry, potential workforce and gentle prevailing winds Bedford was the ideal location.

The site covered 1086 acres and the total cost was just under £750,000 with up to 800 men involved in the construction at any one time. The site included three main parts: a shed for erecting and housing airships; workshops for manufacture and assembly of component parts; and a hydrogen generating and storage plant. There was also an alloy plant with rolling mills, foundry and furnaces along with blocks containing offices, canteens and garages. The site also boasted a model village for the workers, Shortstown.  

The airship shed was built with a steel frame and corrugated iron sheeting and was the largest built in Britain at the time. It measured 700ft long by 235ft wide with a clear span of 180ft and height from floor to ridge of just over 144 ft. Huge windscreens 700ft long and 70ft high were built by the entrances to the shed to protect the airships as they were manoeuvred in and out.

The first airships to be constructed were reproductions of the wooden girder Schutte-Lanz. However, post-war developments led to the design being superceded and the R-38 was constructed for special operations in the North Sea, capable of an altitude in excess of enemy aircraft. During the war over 225 airships were constructed. In particular, they were an effective submarine deterrent when the Navy performed reconnaissance, patrols, mine-hunting and convoy escorting duties. They were responsible for driving them underwater and out of harm’s way where, previously, they had been free to attack. Only once was a ship sunk by a submarine whilst being protected by an airship. Airships also aided the destruction of U-boats. The impact of this was huge, protected shipping could supply arms and goods both to the military and civilian population.

Cardington was one of only a few airship sites to produce hydrogen for the ships by the water gas process, whereby steam was reduced to hydrogen by passing it over lumps of spongy iron at a high temperature. The iron oxide then needed to be reduced back to iron using blue water gas. However, as this process had to be continuous and lacked flexibility, and as it also required a large, complex and expensive fixed plant with skilled operators, it was impractical compared to the German system.

The site was nationalised in April 1919, becoming known as the Royal Airship Works. In the 1920’s the wartime shed was extended and another shed added for construction of the R-101 airship. After the R-101 crashed in October 1930 airship construction was abandoned in Britain.  The sheds have since been used for weather balloons and development of parachutes. Airship design has recently returned to Cardington and the sheds are currently being used to build a hybrid airship, and soon to house the British Airship Museum. Started as an expediency of war, the site became central to British airship design.
Crossing a ditch

Crossing a ditch

by User Not Found | 19 May, 2014
Images showing various stages of the construction of Cardington and the model village for workers.


German U-boat film from the war, airships became a major weapon against submarines.

Caterpillars and Tanks

"It was a weapon designed for one simple task: crossing the killing zone between trench lines and breaking into enemy defenses [sic]." 1

In 1904 David Roberts had patented a train track tractor, trials in 1907 led troops to nickname the track tractor the ‘caterpillar’. A tracked trailer was also designed, on which to load and move guns. The vehicle was devised for transportation; it was not intended as a weapon. It was the expediency of the war that led to further developments. It was the need to mount trenches and break the stalemate of troop/ground warfare that led people to make the association between a tracked vehicle and an armoured vehicle: these concepts would be combined to create the tank. Unlike the caterpillar, the tank had no sprung suspension and the track plates were an improved in order to deal with wartime conditions.

The Ministry of Defence had rejected the idea of tracked vehicles and sold the patent to Holt Manufacturing Company in 1911: the army, therefore, had to purchase caterpillar tractors from The Caterpillar Tractor Company (as Holt had become) for transportation uses in the war.

The tank was not the first armoured vehicle but previous incarnations required level surfaces on which to move. It became increasingly apparent that what was required was a self-propelled vehicle which could run on rough terrain. The urgency for such a weapon was due to the stalemate on the Western Front, where months and many lives were spent edging forwards and back. Trench warfare required a vechile which could overcome rough terraine. Accordingly, the tank was devised to survive artillery fire and move through barbed wire thus progressing into territory troops could not go on foot without severe reprocussions and loss of life. The innovation was eventually successful in attack, although during the First World War it was not realised that 20 years later the tank would be a major weapon of warfare.

The combined efforts of the Admiralty and the War Office led to a prototype being trialled in 1915, it was affectionately known as 'Little Willie'. In early 1916 some changes led to the building of 'Big Willie', officially known as Mk 1 it was also called 'Mother' (to denote how it gave birth to all future tanks and associated developments).

The tank was first used at the Battle of the Somme (1916), its impact was psychological rather militaristic; records show that of the 49 tanks which took part in the engagement, 17 broke down before they reached the front line, 9 more broke down at the front line and 5 got bogged down during the attack. However, its invulnerability to small arms fire and use for subduing machine gun fire and crushing barbed wire was established (this opened the way for an infantry attack to follow). However, as they were sent ahead of artillery barrages all assault surprise was lost. It took until 1917, at the battle of Cambrai, for the tank to show its effectiveness in battle. They were used in large numbers without the following artillery bombardment and the massed surprise assault achieved a spectacular breakthrough.

By the end of the war, engine developments meant faster tanks were being manufactured. It seemed that the Allies, at last, had the answer to the problem of strategic penetration following a break-through. However, the war ended before this could be proven - the British Tank Corps had planned to use 10000 tanks in an independent mass assault. Somewhat ironically, it was for the German Panzer units of the Second World War to prove this.

Crossing a ditch

Crossing a ditch

by User Not Found | 19 May, 2014
The photographs show a range of armoured vehicles used in wartime, primarily as transporters, as well as a prototype tank. To read more on the design and development of the tanks during and since the war click here.
Aircraft

Flying was only 11 years old in 1914. Originally planes were not used for defence but for recognisance: photographing positions/battle sites and as radio cover for troop movements during battle. At first the weight of weapons and their interference with the propeller meant that they were not armed with a forward firing machine gun, meaning they could not be used as a weapon. The invention of the interrupter gear (a synchronization device which meant bullets did not shoot the propeller) in 1915 was a major engineering development which made aerial warfare possible for the first time. It also signifies the technological battle raging between the two sides. Roland Garros, a French army aviator, had a Morane-Saulnier Type L with gun fitted: he shot down the first ever aircraft (German) with a tractor propeller on 1 April 1915; this was followed by two more successful 'kills'. On the 18th he was captured by the Germans but he failed to destroy his aircraft completely before being taken prisoner: most significantly, the gun and armoured propeller remained intact. Apparently this led engineer Anthony Fokker to design the improved interrupter gear system; in truth he had been working on it for at least six months but it is plausible the discovery and study of a working interrupter advanced his work. It was now the Allied planes that were in danger, such was the impact of his invention that the ensuing ascendancy in the air of the German's became known as the Fokker's Scrouge.

In fact the work on Fokker's system had been going for at least six months before Garros' aircraft fell into their hands. With the advent of the interrupter gear the tables were turned on the Allies, with Fokker's planes shooting down many Allied aircraft, leading to what became known as the Fokker Scourge. The Allies were essential defenceless. Technology caught up and by the summer of 1916 the Allies also had forward firing machine guns with new lighter/more agile planes. Their recognisance role remained vital however for example, playing a key role at the Battle of the Somme.

Aircraft was also used against the German U-boats, taking off initially from ships. In 1916 the Blackburn Aircraft Company designed and built two prototypes of an anti-submarine floatplane, the Blackburn General Purpose. On their own initiative Blackburn then developed a landplane version, the Blackburn R.T.1 Kangaroo (Reconnaissance Torpedo Type 1). Test results in early 1918 were disappointing, with the rear fuselage being prone to twisting and the aircraft suffering control problems, the order was cut from 50 to 20. However, a more powerful Rolls-Royce Falcon III engine replaced the 250 hp (120 kW) Rolls-Royce Falcon II that had been used. The Kangaroo entered service with No. 246 Squadron RAF and saw six months of operations, sinking one U-boat and damaging another four. After the war they were converted for civilian use, being used as a regular passenger service between Roundhay Park (Leeds) and Hounslow Heath, then in 1920 onto to Amsterdam. On 21 November 1919, one Kangaroo (G-EAOW) took off from Hounslow Heath in an attempt to win the Australian government prize of AUD 10,000 for the first Australian airman to fly a British aircraft from the UK to Australia within 30 consecutive days. The Kangaroo was forced to make an emergency landing at Suda Bay, Crete with a suspected sabotaged engine, and the aircraft was abandoned there.

Crossing a ditch

Crossing a ditch

by User Not Found | 19 May, 2014
Design drawings for Whitworth-Armstrong Vickers machine gun mount. See more on the Resources page.

Anthony Fokker with his plane
Fokker with the plane he obtained his flying license in, 1911. He is chatting to pilot Nyenhoff, who flew it in an air show in 1936.

Blackburn Kangaroo
Blackburn Kangaroo, preparing to fly in Australia in 1919.

Credits/footnotes:

​Williamson Murray, "Armoured Warfare: The British, French, and German Experiences," in Murray, Williamson; Millet, Allan R, eds. (1996). Military Innovation in the Interwar Period. New York: Cambridge University Press. p. 6. ISBN 0-521-63760-0.

Images:

Paravane design drawings; The Mk I tank ‘Big Willie’; Aircraft images; and machine gun mount design drawings/papers.  IMechE Archive.

Photographs of  track tractors being used in South Africa, ICE Archive.