Tank Turret Fortifications

Neil Short

• Publisher: Crowood
• Year: 2011
• ISBN:
  9781847973672
• Topic: History
• Subtopic: Military & Maritime History
• Index: History

Tank Turret Fortifications traces the origins of the idea from the development of the first armoured turrets in the nineteenth century through to the present day. On the way it covers the inter-war period when the first turrets were used in this way, the Second World War, when tank turrets were used on every front in the European Theatre of Operations, and the post-war period, when tank turrets were used even more widely. The book also details the decline of the idea as countries reassessed the threats they faced and slowly dismantled all their fixed fortifications. Widely used during World War Two and since, tank turret fortifications deserve a history, and Neil Short has spent several years writing this, the first proper study.

1 The First World War

Even before the First World War tremendous strides had been made in the development of armoured turrets. The British navy had initially developed the idea as early as 1855 in order to protect guns and their crews from enemy fire and by the 1870s the concept had been adopted by all the major navies of the day. The potential for using this idea on land was soon recognized and despite initial concerns about the robustness of the structure, a decision was taken to mount a two-gun turret at Dover. This, like the turrets mounted on board ship, was little more than a covered circular box with ports for the guns.

On the continent, the Grüson company of Magdeburg, Germany in the 1860s had developed a technique for producing cast iron curved sections which could be ‘welded’ together to form a complete cupola which rotated on a turntable of rollers. One such turret, mounting two 16in guns weighing 120 tons, was used by Krupp to protect the Italian naval base at La Spezia.¹ And it was not long before the wider possibilities of using such turrets were recognized. The Belgian General Brialmont was a keen advocate of the idea and proposed using both fixed and retractable turrets and in 1865 he installed an armoured turret in the reduit of Fort III protecting Antwerp. A little later, Maximilian Schumann, a Prussian army engineer and subsequently chief turret designer for Grüson, designed a series of increasingly sophisticated armoured turrets to improve the protection for the gun and its firing ability, his work culminating in the design for a retractable turret.

In France, Mougin, designer for the St Chamond gun-making company, also developed a number of armoured turrets, one of the best known being the cast iron turret mounting twin 155mm long-range de Bange guns. Twenty-five of these were built as part of the Séré de Rivière fortifications; a series of fortifications that stretched from the English Channel to the border with Italy.⁽¹⁾²

Thus, by the end of the nineteenth century a number of companies were producing and selling armoured turrets. However, despite the fact the German company Grüson was one of the leading manufacturers of this technology, there was disagreement in the Imperial Army about how best to use armoured turrets in fortifications. What was clear though was that with the advent of the explosive shell open gun positions were no longer practical and some sort of protection had to be provided. In 1892 the first fort was built using armoured turrets. This included fixed and retractable turrets and additional firepower was also provided by the Grüson turret, or Fahrpanzer. This weapon is of particular interest because it was the precursor of the French tourelle démontable which formed part of the Maginot Line defences (and which is covered in more detail in the Interwar section of this book) and as such was arguably a forerunner of the Panzerstellung.³

During the First World War the Germans installed old naval guns along the coast. ‘Lange Max’ or ‘Long Max’ was located at Moere, about 8 miles from Ostend. The 38cm gun was used to shell Dunkirk.
(Author)

The main body of the Fahrpanzer consisted of a cast-iron cylindrical base topped with a cupola that housed the main armament. It was 1,655mm (65in) high and 1,540mm (60in) round with 40mm (1½in) thick armour that provided the crew with adequate protection against shrapnel and small arms fire. A door at the rear gave the crew access to the fighting compartment.

The main body of the structure was set on four rollers some 60cms (24in) apart, which enabled the turret to be moved on tracks into a pre-prepared semi-circular concrete niche to augment the main armament of the fortification. When not in use it could be rolled back into a covered position for protection. These rollers also enabled the turret to be moved onto a specially designed carriage that allowed it to be moved more easily around the battlefield. This had four wheels – two larger wheels at the rear that bore the weight of the turret and weapon and two smaller wheels at the front on a pivot point to enable the carriage to be turned.⁽²⁾ The wheels were somewhat unusual in that they were made of wood with a steel tyre, whereas the rest of the structure was constructed from iron. This arrangement may have been developed to smooth the ride, since the carriage had no suspension.

A seat at the front of the vehicle accommodated the driver who drove the three horses, which were attached to the carriage by a limber. A hand-operated wheel under the driver’s seat applied a brake to the larger wheels at the rear when the carriage was stationary.

The Fahrpanzer was arguably an early forerunner of the panzerstellung. This example was captured by the Greeks in the First World War and is now housed at the Greek War Museum in Athens. The cast-iron cylindrical base and the domed turret that housed the main armament are both clearly shown. (Author)

The Fahrpanzer could be mounted on a specially designed carriage. The access hatch to the turret is visible behind the driver’s seat. Just below the hatch it is possible to see one of the rollers that enabled the turret to run on tracks.
(Author)

Inside the turret a pedestal was located centrally with three branches rising from the centre to support the cupola. This sat on the main body of the structure on a series of small wheels and was rotated using a large hand wheel that permitted a full rotation of the turret in 15 seconds. A simple mechanism enabled the turret to be locked in position so that it did not deviate when fired. Around the inside of the turret was a band marked in degrees, which enabled the crew to accurately rotate the cupola. Two simple seats were provided for the gunner and loader/commander, which were attached to the pedestal. The ammunition (circa 130 rounds) for the weapon was stored vertically in racks at the base of the structure.

An inside view of the Fahrpanzer turret that clearly shows the gun breech and elevating gear. The central pedestal is also visible as is the small vent at the top.
(Author)

The main armament was mounted in the cupola above a shelf. The gun trunions were secured to the shelf and there was no recoil mechanism. The gun was fitted with a simple falling type breech with the breech handle on the right and the elevation mechanism on the left. This consisted of a vertically mounted screw thread affixed to the breechblock and the shelf of the turret. By rotating a hand wheel the gun could be elevated and depressed +10 to –5 degrees. This set-up allowed for some very fine adjustments to be made, but it was not suited to quick changes in the angle of depression or elevation when in combat.

The 53mm Schnelladekanone could fire either high explosive or case shot. Its maximum range with HE shells was 3,200m (10,000ft) and 400m (1,300ft) with the shot. The simple breech mechanism and the one-piece ammunition enabled the weapon to be fired very rapidly; the crew of two were capable of firing the weapon at 25–30 shots a minute. An opening in the top of the turret was fitted to vent the fumes, but when using rapid fire it is likely that this would have been insufficient and the doors would have to be opened to prevent the asphyxiation of the crew.

The turret was not fitted with an optical sight. A small hole in the dome with aiming point above and to the right of the gun and a sight fitted outside on the barrel enabled the crew to aim the weapon. Additionally a number of vision slits were provided to give the crew greater visibility. These could be covered with armoured plates when not in use. A small rain guard above the weapon prevented any precipitation entering the turret.

Production of the Fahrpanzer began in 1889 and in total some 200 were produced (although other sources state 322). The turrets were exported to a number of countries and were employed by the Central Powers in the First World War.⁽³⁾⁴

By the turn of the century armoured turrets had been sufficiently refined that they were capable of being fitted to armoured cars. The Austrians installed a turret on the Austro-Daimler armoured car of 1904 (and the modified 1905 version) and the French Charron car from roughly the same period also had a turret. During the war all of the major belligerents used armoured cars with turrets. The Italian Lancia armoured car of 1915 was even fitted with a smaller turret atop the main turret. In that same year the Canadian Russell armoured car entered service. This was the first vehicle to have a turret basket that rotated with the turret.⁵

By the outbreak of the war the technology behind armoured turrets was well established. However, the first tanks that were developed were all fitted with fixed guns. For some time before the war experiments had been conducted to assess the effectiveness of caterpillar tracks. These peacetime trials led to the development of simple farm tractors. But with the outbreak of war these experiments were given added urgency as the British actively pursued this idea as a possible solution to the stalemate on the Western Front. An armoured vehicle fitted with tracks, it was hoped, would be able to advance across the broken terrain and engage enemy positions that had survived the preparatory bombardment and together with supporting infantry might offer the prospect of the thus far elusive breakthrough.

In Britain, somewhat unusually, the research was undertaken by the Royal Navy with the full support of the First Lord of the Admiralty, Winston Churchill. The first prototypes of the ‘tank’⁽⁴⁾ were tested in September 1915 and were introduced on the Western Front in the latter stages of the Battle of the Somme in September 1916. In the spring of the following year the French fielded some 130 so-called ‘assault cannons’ in the action at Chemin des Dames.

A First World War British tank knocked out at Langemarck. The initial British a...