German self propelled guns of ww2 Nazi Germany
Self-propelled superheavy siege guns – None Built

“It seemed like a good idea at the time”

Times of war can lead to unorthodox solutions to unforeseen problems. Sometimes these are successful; the Duplex Drive tank, the jet engine, night vision, and reactive armor. Sometimes these aren’t so successful…

The designs talked about here are not among the former. This article is a collection of little-known projects by Nazi Germany to mount naval artillery, super heavy siege cannons, and railway guns on the combined chassis of two or more tanks. These designs are quite obscure and do not have enough information to warrant their own individual articles.

Projekt NM

Coming from 1943 is possibly one of the strangest ground fighting vehicles ever designed; the Project NM was a massive wooden warehouse structure atop a steel girder frame transported by three turretless Tiger Ausf.E tanks. The entire assembly measured about 17 meters wide by 15 meters long. Inside the wooden warehouse were three turrets mounted line abreast armed with 12.8 cm cannons. The center turret was slightly staggered behind the other two. The cannons pointed back over the rear of the vehicle, poking out through the doors of the warehouse. At the ‘front’ was a single Tiger tank while the other two Tigers were under the rear.



There are two schools of thought as to what the purpose of this vehicle was. The first is that it was destined for use on the plains of the Eastern Front, but there are several problems with this. Firstly, a large warehouse slowly creeping across a field isn’t very inconspicuous. Second, the NM would be unable to cross rivers, neither by fording, due to the rigidity of its construction, nor by bridges, due to its width. As a rigid structure, the NM would be unable to cope with all but the slightest changes in ground slope.

The second possible use for the vehicle is as a mobile coastal defense installation, for example as part of the Atlantikwall. This seems the more reasonable use, as a warehouse on the coastline isn’t likely to draw attention. Just who the project is attributed to is unknown as well, whether it was the Heer (Army) or the Kriegsmarine (Navy). Suspected use, armament, and the name all point to it being a Kriegsmarine project. The Kriegsmarine often designated their projects with capital letters, while the Heer did not. The armament, consisting of three 12.8 cm guns in separate turrets is another indication that the NM was a Kriegsmarine project. The Kriegsmarine referred to all their 128 mm guns as 127 mm guns, probably in order to avoid confusion with the Heer’s cannons. Assuming the NM was a Kriegsmarine project, its armament would have been either 12.7 cm SK C/34, or 12.7 cm SK C/41 cannons, though the former is the more likely choice, as they were more widely used.

Operationally, the NM would likely be deployed to a coast region where an attack was expected, or where the defense needed strengthening. The vehicle would be reversed into position and possibly camouflaged to best appear as a non-threatening structure. When an enemy vessel was within range the doors of the warehouse would be opened, giving the guns a reasonable firing arc. The NM would have time enough to fire a few salvos before the enemy vessels finally realized they were being engaged by a warehouse and not surface vessels or gun emplacements. When return fire started coming in, the NM could drive forward to move itself out of the line of fire.

Unsurprisingly, attaching three Tiger chassis together with steel girders and putting a warehouse on top wasn’t seen as a very practical idea. The NM Project did not advance any further.


Projekt NM Blueprint (Source: Der Panzerkampfwagen Tiger und Seine Abarten – Walter J. Spielberger, 1997)

Tiger H als Tragfahrzeug für schwerste Geschütze

In January 1941 (perhaps this was a typo for 1942, as the project is only mentioned again in December of 1942, nearly two years later), the Waffenamt (German Army Weapons Agency) put out a requirement for a system for transporting the 24 cm Kanone 4.

The K 4 was a project to upgrade the underwhelming 24 cm K 3. Only 14 K 3 guns were built; the reason being was that they were much more time-consuming to set up and operate than comparable guns such as the 21 cm Mörser 18, while their advantage in performance was not significant enough to warrant the hassle. Little information is available on the K 4, other than basic measurements. The barrel length was a ‘L/72’ meaning it was 72 calibers long. (72 x 24 cm gives a total barrel length of 17.28 m) and the gun was meant to fire 160 kilograms (353 lb.) shells up to 49 kilometers (30.4 miles).

Both the firms of Krupp and Rheinmetall-Borsig responded to the requirement. Krupp’s design was to use two unarmored Panzer VI Tiger chassis; while Rheinmetall’s design used the Karl-Gerät chassis. Further information on Rheinmetall’s design is unavailable; presumably, it was rejected early on due to the Karl Gerät chassis being too slow and unmaneuverable.

On the 17th of December, 1942, the OKH (German Army High Command) sent letter Wa J Rü (WuG 6) Villa2 Nr. 9846/42 to Henschel, the manufacturer of the Tiger chassis, requesting the necessary parts to build a prototype. Assembly of the vehicle was to take place at one of Krupp’s plants. The order was signed under the name “Tiger H als Tragfahrzeug für schwerste Geschütze”, or “Tiger H as a carrier for the heaviest guns”.

Krupp’s design aimed to have greater speed and mobility than the lackluster Karl Gerät. The unarmored Tiger chassis weighed 25 tons each. In order to prevent one tank moving while the other wasn’t, which would have damaged the machine, the drive units of each chassis were intended to be hydraulically linked to stay at the same speed. The projected top speed was 30 to 35 kph (18.6 to 21.7 mph). Hydraulic jacks were to be installed in place of the turret in the Tiger chassis; these would support large cylinders which in turn supported the gun platform. The gun platform could be lowered onto its base plate and the Tigers driven away with minimum difficulty. Four outriggers would be deployed to stabilize the gun. Whether or not the gun had any reasonable degree of traverse once in firing position is unknown.

The gun platform was lowered in the center, like a heavyweight railroad flatcar, but even so, the assembly was more than twice as tall as a normal Tiger tank when in transport configuration. Additionally, the ground pressure for each unarmored unit was significantly higher than a normal Tiger tank. However, being too heavy to cross bridges was not seen as a concern as only one load-bearing unit would be on the bridge at one time, due to the vehicle being so long. The distance between the centers of the Tiger chassis was to be 20 to 22 meters (65.5 to 72.1 feet), to give a sense of scale, a normal tractor-trailer truck trailer is 53 feet, or 16.1 meters long.

On the 23rd of December, 1942, Henschel stated that they would be unable to produce more Tiger chassis for a Lastenträger vehicle alongside of normal Tiger production, as they were already at full capacity.

A single prototype of the K 4 was being constructed at Krupp of Essen, but this was destroyed in a bombing raid in March 1943. With the destruction of the prototype, the K 4 project was canceled. If it had not been canceled already, this was surely the death of the Tiger H als Tragfahrzeug für schwerste Geschütze as well.


24 cm Kanone 4 mit Lastenträger Tiger I (Drawing Copyright Hilary Louis Doyle)

Gerät 566 Lastenträger 606/5 für K 5/3 (Tiger)

As the first design was canceled due to the discontinuation of the intended weapon, and not because it was ridiculous and impractical, Krupp decided to persevere with the tank-based railway gun idea using the 28 cm K 5 instead. The K 5 (sometimes incorrectly referred to as Leopold – this was the name of an individual railway gun rather than the name for this system) was the most successful railway gun of World War II; 25 pieces were built in total. The railway version of the gun weighed 218 metric tons; this number is probably not far off from the weight of the tank-based gun had it been built.

To transport the K 5 Krupp chose the Panzer VI Tiger II chassis. The general construction was similar to that of the first design, however, it seems the second design had even thinner support cylinders. Coupled with the immense weight of the K 5, it is even more unlikely the mechanism for raising the gun into transport position and lowering the gun into firing position would be functional and reliable.

Note: The book ‘Der Panzerkampfwagen Tiger und Seine Abarten’ (Spielberger, 1997) seems to suggest that the gun barrel, gun carriage, and base plate were all transported separately. However, the same book shows the illustration below, which implies that the whole assembly was transported as a single unit. Transporting the weapon in pieces would help overcome the problems of its great size and weight, but would make assembly upon arrival a nightmare. The book also states that a separate Tiger II-based vehicle would bring along “closing pieces” for the gun.

The Gerät 566 Lastenträger 606/5 für K 5/3 (Tiger) would have used a late-war development of the K 5 gun; the K 5 Glatt. The K 5 Glatt had a 31 cm smoothbore gun tube that was designed to fire 136 kilograms (300 lb.) subcaliber fin-stabilized rounds called Pfeilgeschoß up to a range of 120 to 150 kilometers (74.5 to 93.2 miles). This was great enough range to fire on London. However, due to the implementation of the V1 ‘Buzz Bomb’ and V2 missile, the K 5 Glatt fell by the wayside. Only two were built, both in railway configuration.


28 cm Kanone 5 mit Lastenträger Tiger II (Drawing Copyright Hilary Louis Doyle)

28 cm Düsenkanone auf Panther Langholzprinzip

It seems that when Rheinmetall-Borsig got wind that their rival was designing a tank-based 28 cm gun, they decided that they could do it better. In a drawing dated from September 1943 Rheinmetall proposed that two Panzer V Panther chassis be used to carry a 28 cm L/52 cannon. The only 28 cm cannon with a barrel length of 52 calibers available to the Germans was the SK C/28 naval gun. These were the guns used on the Deutschland-class battlecruisers and were the proposed armament for the Landkreuzer P.1000 Ratte. However, the designation of the gun, Düsenkanone, means that it was intended to be recoilless. Whether or not the 28 cm Düsenkanone was developed from the SK C/28 or was an independent design is unknown at this time.

The name of Rheinmetall’s design was the 28 cm Düsenkanone auf Panther Langholzprinzip, which translated to English means 28 cm Recoilless Cannon on Panther Long Wood Principle. “Langholzprinzip” is the German term for the practice used in logging whereby fallen trees are attached to a truck at one end and to an independent set of trailing axles at the other. By doing this the logs are allowed to support themselves between the axles and negate the need for a trailer. This same principle was employed on the 28 cm Düsenkanone auf Panther, with one tank taking the place of the truck, and the other taking the place of the trailer, leaving the payload slung between them.

The first Panther had a support that would attach to a collar half-way up the 28 cm DüKa’s barrel, while the second Panther had a large, crane-like structure that would hold the gun’s breech from above. In order to fire, the gun would be lowered to the ground by large hydraulic rams inside the hulls of the tank chassis. The Panthers would then disconnect from the gun and move away. The cannon could then be used as a normal gun emplacement, able to rotate on its pedestal. Inside the gun’s superstructure was stored 10 two-piece rounds.

Despite the fact that Rheinmetall’s design was much more practical than Krupp’s design, perhaps even useful, the project did not advance any further.


28 cm Düsenkanone auf Panther Langholzprinzip Blueprint Source

Epilogue

Nazi Germany is remembered, among other things, for hideously impractical, ludicrous ‘wonder weapons.’ The idea of making railway guns mobile by sticking multiple tanks together is probably one of the weirdest. In the end even the Nazis had enough sense to see that these designs were hopelessly impractical.

However designs for vehicle-based super heavy siege guns did go on, with such things as the 58 ton Grille 17/21, the 182 ton R 2, and the 1500 ton Landkreuzer P.1500. None of these designs made any impact on the course of the war; only the Grille 17/21 was partially built while the others remained on paper. The only design of this type to become operational, the Karl Gerät, remains a lasting symbol of Hitler’s megalomania and the embracing of unconventional designs by the Third Reich’s war machine.

Sources

Les Armes secrètes du IIIe Reich: Hitler aurait-il pu gagner la guerre? – Laurent Tirone, 2014
Enzyklopädie Deutscher Waffen 1939-1945: Handwaffen, Artillerie, Beutewaffen, Sonderwaffen Gebundene Ausgabe – T.J. Gander and Peter Chamberlain, 2008
Der Panzerkampfwagen Tiger und Seine Abarten – Walter J. Spielberger, 1997
Panther Variants 1942-1945 – Osprey New Vanguard, 1997

Germans Tanks of ww2
Germans Tanks of ww2


Tank Encyclopedia’s own illustration of the 28 cm Düsenkanone auf Panther Langholzprinzip by Jaroslaw Janas.

Grille 17/21 Self-Propelled Guns
Waffenträger Panthers - Heuschrecke, Grille, Skorpion
Share →

17 Responses to German Tank-based Railway Guns

  1. Zarax says:

    Wow, this is super interesting. Never knew these things existed. Keep up the good work!

  2. Markus Nolte says:

    “Langholz” is the German term for long pieces of unprocessed wood f.e. whole tree trunks. To transport them, you put one end on a truck and the other end on a wheeled bogie. The bogie is connected to the truck only by the load. The 28 cm DüKa is transported in the same way because the barrel is resting directly on the front tank like a log. DüKa is short for “Düsenkanone” or recoilless gun. If you look closely at the drawing, you will see the nozzle at the rear of the breech.

    • Zarax says:

      Oh boy, so you are saying these things were recoilless ? How did that even work?

    • Hunter12396 says:

      Very interesting, thank you for the explanation! The article will be corrected shortly.

    • Markus Nolte says:

      I found some more information on the 28 cm DKM 44: It was planned for the Kriegsmarine as a coastal defense gun by Rheinmetall.
      One prototype was build. It would have fired a 315 kg shell with a Vo of 750 m/s. The gun would have had a weight of 28 metric tons und the barrel was 14,4 m long. (Gander/chamberlain Small Arms, Artillery and Special Weapons of the Third Reich, London 1978, no picture)
      Using this behemoth as coastal defense on prepared positions would have made some sense, transferring it between positions by some sort of motorized transport too. But why using tanks an not a railway gun or, like with the 12,8 cm Flak-Zwilling (~48 tons), a wheeled trailer?

  3. Roger Greenaway says:

    The “Langholz Prinzip” refers to the method of transporting felled trees. One end of the trees rested on the truck, the other end on a separate bogie, which is still in use today. If you google the expression, you’ll find examples of modern transporters.

  4. Gustave says:

    Do you have any sources for any of this information?

  5. SSSmk2A4 says:

    I don’t know if the Soviets inspired by this project, but in Cold War there was a similar attempt for moving large object with two tracked chassis.
    Not a big gun, but a ballistic missile.
    Here, in Броня России episode 9, (8:15 to 9:20) https://youtu.be/1TpIV-ODvcI?t=8m15s
    Based on auto-translate subtitle, it was only prototype. Total weight of the installation is 70-80 metric tons. The tracked chassis looks like derived from T-64.

  6. mitallem says:

    To what does the “182 ton R 2” refer to? I’m really curious about it, but wasn’t able to find anything by myself. I’d be very thankful if you could help me out. Thanks.

Leave a Reply

Your email address will not be published. Required fields are marked *