120 mm and 150 mm howitzers

Introduction

When (for the Dutch) war broke out in May 1940, the army had no less than four different types of howitzers in service. None of these howitzers was of a true modern type, but the existing WWI era arsenal still proved its value during the battles in which they were called into action. We shall briefly elaborate on all four types.

The Dutch howitzers - a story of missed opportunities

The Dutch army had a limited number of howitzers available when in 1914 WWI broke out; a few dozen Krupp and ten Bofors 12 cm howitzers were all there was. This situation improved after WWI, due to the fact that the military strategists realized that medium cal howitzers were essential in a modern army. But - the pacifism that gained ground after the terrible Great War combined with the terrible crises in the 20's saw all defence-funds dry-up thus preventing the army from cashing their desire to expand the artillery with more than a few howitzers. As such only a few dozen 15 cm howitzers had been procured from British war-caches (including German loot). Only five light howitzer and eight medium howitzer batallions could be formed from the existing arsenal and the additional purchases.

The Dutch military demanded additional medium cal artillery, but besides a series of purchases that obtained a total of 52 modern Bofors 10,5 cm field guns, no new medium calibre piece were obtained after 1920. When the tension in Europe grew, new demands were filed at the cabinet of the defence ministre, but in vain for a long time. When finally a go-ahead was received to obtain new equipment, it took the chain of decision makers so long to decide on a type and make, that when they turned to the market, it had been overloaded with demands. The Dutch were too late. It forced the defense purchasers to turn to German makers, well aware of the risks of non-supply from that source. Finally 120 off medium (10,5 cm) howitzers were ordered at Rheinmetall.  It goes without saying that besides the delivery of eight 'test and school pieces' that the Dutch never received the actually produced and ready main production batches. Those were confiscated by the German weapons commission, that had to sanction any weapon delivery. The planned purchase of modern 15 cm howitzers never even materialized.

When the war broke out in the west, the Dutch army had to fight it with its modest arsenal available. In total four types of howitzers served in the Dutch army in May 1940: it were 12 cm Krupp and Bofors and 15 cm Krupp and Vickers. All of these types had been procured in the era 1908-1920.

Howitzers of 12 cm

In 1908 the first howitzer was adopted by the Dutch army. It was again a Krupp product, but not one of the best weapons this company produced. The very short barrelled Krupp 12 cm M1905 howitzer would therefore not become the standard light howitzer for the field-artillery during the 1908-1918 period. The Dutch bought only 10 pieces of which 8 would still serve in 1940 in 27.RA.

The Krupp 12 cm howitzer was a shelf howitzer, easily produced of ready parts of the Krupp stock. It was considerably outdated when WWI ended. The short barrel of the gun limited the range of the weapon to no more than 5,800 meter and the rapid-fire characteristics were quite poor due to the fact that the gun was constructed of low alloy steel.

The Krupp 12 cm howitzer was operated by six men and a gun-commander. It was usually pulled by four heavy-duty or six ordinary horses. The weapon was capable of delivering two sorts of ammo: HE or HE canister.

Specifications 12 lang 12

Manufacturer: Krupp (Germany)
Model [Dutch registration]: 12 lang 12 (12hwL12; 12.12)
Calibre: 120 mm (barrel length 1440 mm)
Fire rate: 2 rounds per minute, max 5 minutes
Elevation / traverse: 0°/+45° ; traverse 0°
Undercarriage: Scooped, with sectional cradle
Muzzle velocity V0: 300 m/s
Ammunition types: HE and HE canister (20,4 kg)
Weight: Gun: 1.177 kg
Barrel: 470 kg
Traction: 4 heavy duty or 6 regular horses
Max. range: 5.800 m.
Crew: 6 men plus commander
Year of introduction: 1908
Number available in May 1940: 10


Another 12 cm howitzer that was introduced pre-war was a Bofors 12 cm weapon. This was a gun of better quality (nickel-steel) than the steel Krupp. Twelve field batteries were equiped with this gun. The outbreak of WWI prevented procurement of more Bofors howitzers. All these guns were still operational in May 1940 in III./1.RA, III./2.RA, III./4.RA and III./7.RA.

The Bofors was first tested in 1911. The gun was constructed of nickel-steel and capable of rapid-fire, what in those days meant that 3 rounds per minute could be fired. The other basic features of the gun were quite similar to the Krupp, of which it seemed to be a remarkable copy. With exception of the slightly longer barrel [14 x calibre], the gun had the same performance envelop - although it was able to produce rapid-fire. The maximum range was also 6,100 meter and it was capable of firing HE and HE canister too.

The 12 cm howitzers were quite extensively used during combat in the battles for Valkenburg (the shelling of German occupied airfield) and later the siege of trapped German airlanding forces between Delft and Rotterdam.

Like the Krupp, the Bofors 12 cm howitzer crew comprised six men and a gun-commander. The gun was transported by a span of six horses.

Remarkably enough there are only traces of the Bofors howitzer being adopted in the Germany army [under registration "12.0 cm lFH 373"]. Of the Krupp 12 cm howitzers no trace can be found in German documents (sofar).

Specifications 12 lang 14

Manufacturer: Bofors (Sweden)
Model [Dutch registration]: 12 lang 14 (12hwL14; 12.14)
Calibre: 120 mm (barrel length 1725 mm)
Fire rate: 3 rounds per minute, max 5 minutes
Elevation / traverse: 0°/+45° ; traverse 0°
Undercarriage: Scooped, with sectional cradle
Muzzle velocity V0: 300 m/s
Ammunition types: HE and HE canister (20,4 kg)
Weight: Gun: 1.610 kg
Traction: 4 heavy duty or 6 regular horses
Max. range: 6.100 m.
Crew: 6 men plus commander
Year of introduction: 1908
Number available in May 1940: 48
Remarks: Fitted with 5 mm thick armoured shield.


Howitzers of 15 cm

Although hardly any funds were made available for expansion of the army after the devastated economic situation the Netherlands were in after the Great War, it was imperative that some medium calibre howitzers would be procured. Two types of howitzers would reinforce the artillery in the interbellum.

The first 'new' howitzer was introduced in 1919 when a number of 15 cm Krupp howitzers were bought out of Allied loot from German stock-piles. In total 44 off Krupp howitzers of the [Dutch designation] type 15 lang 17 would serve in Dutch service of which 40 were active in four arty batallions during the May war.

This howitzer was identical to the German "Schwere Feldhaubitze 150 mm sFH.13". It was a Krupp product and the modification of the older sFH.02 that had a shorter range. It was one of the standard howitzers during WWI of which the German companies Krupp and Rheinmetall would produce 3,409 pieces. It was a very robust and reliable nickel-steel gun and outperformed many competitive guns for its record barrel-endurance. Only after 25,000 rounds the barrel was worn-down to such extend that replacement was required. This feature made it an ideal WWI gun, for logistics were a disaster during that war.

The German army themselves still had over 700 of these howitzers in service in 1940 and some were even mechanized when mounted on armoured cars or Pz.I chassis. A known variant of this weapon was the Lorraine Schlepper [Sd Kfz 135/1]. The Lorraine was a captured French vehicle. Of this mechanised gun about 100 pieces served in Africa.

The Dutch artillery had four artillery battalions equipped with the howitzer 15L17. They performed quite well, although only one out of the four battalions really saw considerable action [battle at the Grebbeberg].

Like the light howitzers of 12 cm, the Krupp 15 cm howitzer had quite a limited range. The gun was capable to deliver a HE load over 8,500 meter max. The gun operation was relatively slow, which caused the fire rate at the highest speed to be 5 rounds per two minutes. This rate could be maintained for five minutes maximum and could only be achieved with an excellent crew.

The gun-crew comprised six men and a commander. The howitzer was pulled by six heavy duty or eight regular horses. For heavy terrain conditions a span of another two horses was added.

The Germans captured the majority of the guns intact after the capitulation and adopted them in their ranks under the registration 15.0 cm sFH 406.

Specifications 15 lang 17

Manufacturer: Krupp (Germany)
Model [Dutch registration]: 15 lang 17 (15hwL17; 15.17)
Calibre: 150 mm (barrel length 2550 mm)
Fire rate: 5 rounds per 2 minutes, max 5 minutes
Elevation / traverse: 0°/+45° ; traverse 10°
Undercarriage: Scooped, with sectional cradle
Muzzle velocity V0: 385 m/sec [40,2 kg] 365 m/sec [42,3 kg]
Ammunition types: HE and HE canister (31,9; 40,2; 42,35 kg)
Weight: Gun: 3.500 kg
Barrel: 2,135 kg
Traction: 6 heavy duty or 8 regular horses
Max. range: 8.675 m. [German HE] 8,500 [40,2 kg Dutch HE]
Crew: 6 men plus commander
Year of introduction: 1918
Number available in May 1940: 44


The Dutch were offered to procure relatively cheap howitzers from the British War Office stock in 1920. The British had a large oversupply of 6 inch howitzers after the war. Since this bargain was too attractive to refuse the Dutch bought 30 (or 32) pieces. The howitzer was designated "15 lang 15". All 30 guns were still in service in 1940, of which 28 would actually be deployed in action.

The subject 6 inch Vickers-Armstrong howitzer was a direct descendant of the previous weapon with a lighter barrel construction. It was a British standard to identify the barrel weight with "cwt". The original British standard 15 cm howitzer was specified as fitted with BL 6"30 cwt. This means in plain English: barrel of 6 inch calibre and 1,524 kg weight [1 cwt = 112 lbs = 50,8 kg]. This gun had a very limited range of 4,700 meters and a maximum elevation of 35°. The British War Office ordered an improved barrel for the gun in 1915, which resulted into a howitzer that became the standard medium howitzer of the British army during WWI. The modified gun was totally different from the 30 cwt version. The barrel was much heavier, the maximum traverse angle had increased to 45° and the breech-block was modified to a screwed semi-automatic device. Moreover, the recoil action was better controlled. The 30 cwt version had a gun recoil action of three full wheel-spins; the new gun had a recoil action of only 61 cm maximum.

This howitzer proved to be such a huge success during WWI that it would become the father of many howitzers to follow. No less than 3,622 pieces served during the war, and this collective hammered a mere 22 million projectiles on German positions!

The Dutch modified the wheels of this field-howitzer by adding a rubber tire around the wide steel wheels to make them easier transportable on the road. Also cartridges and grenades were produced by the Dutch industry, which products failed to meet the powerful British cartridges and excellent ballistic features. As a consequence the range of the howitzers decreased quite dramatically. The howitzer 15L15 was designated to be replaced by modern field artillery end of the thirties. Since the Dutch endeavours for procurement of new 10,5 cm and 15 cm guns failed dramatically, the Vickers howitzers was maintained in the field-army and served as Corps artillery in the rear of the prepared Grebbeline.

The gun-crew comprised 8 men and a commander. The howitzer was pulled by six heavy duty or eight regular horses. For heavy terrain conditions another span of two horses was added.

The Germans captured almost all howitzers intact and adopted them under registration 15.2 cm sFH 407. Also Belgian [15.2 cm sFH 410], Italian and British [15.2 cm sFH 412] equivalents were captured.

Specifications 15 lang 15

Manufacturer: Vickers Armstrong (UK)
Model [Dutch registration]: 15 lang 15 (15hwL15; 15.15)
Calibre: 152 mm (barrel length 2300 mm)
Fire rate: 2 rounds per minute, max 5 minutes
Elevation / traverse: 0°/+45° ; traverse 16°
Undercarriage: Scooped and expansion-brake, with sectional cradle
Muzzle velocity V0: 427 m/sec [39 kg]
Ammunition types: HE and HE canister (39 kg British, 44,84 kg NL)
Weight: Gun: 3.690 kg
Traction: 6 heavy duty or 8 regular horses
Max. range: 8.400 m. [Dutch HE] 10,400 [British HE]
Crew: 8 men plus commander
Year of introduction: 1920
Number available in May 1940: 30