Does anyone here have any experience with the Oto Melara Model 56 Pack Howitzer?

[STURM]

Does anyone here have any experience with the Oto Melara Model 56 Pack Howitzer? The reason I'm asking is because it has been mentioned - despite the usefulness and popularity of the Model 56 - that a major problem encountered by users is that this gun was very prone to damage when towed over long distances. It seems the undercarriage and the connectors [for taking the guns apart] often suffered metal faitigue and that as they were made of alloy, were not reweldable.

I recall reading [on the 1980's] that the Australian and New Zealand army had problems with the Model 56 [with led to the introduction of the Hamel]. One of the problems was probably the lack of range [maximum of 20 kilometres with the M1 round] but what were the other issues with the Model 56?

 

[Abraham Gubler]

Yes I have personal experience of the L5 pack howitzer which was the British version of the Model 56.

As to towing the L5 was speed limited to I think around 40 or 50 kph on roads (20 kph offroad) because of the lightweight wheel system. However the standard way of moving it around was to portee the gun. Because it was very light and could be disassembled the gun would just be loaded onto the back of a truck (or inside an APC) and driven around this way. It would only be towed by a truck for short tactical moves from firing position to firing position.

The range of the L5 on full charge was only about 10 km. And it was not the kind of gun you would want to fire often at full charge. So typical ranges were between 5-8km. It was a very good direct fire gun. The suspension could be lowered so the gun ordnance (barrel and breech) was only a few cm off the ground. You could hide it in a bush beside a road and no tank (or more often recce patrol) could survive driving past you. The role of the gun was to be a mountain gun for rapid deployment and in and out of hard to get places. And its shortcomings as an artillery piece were acceptable because where it was to be used it was either the L5 or nothing.

The big problem the Australian Army had with the L5 was its lack of robustness meant it could not provide sustained fire support. So in VietNam they were quickly replaced with the M2A2 (aka M101) 105mm howitzer which was twice the weight but a lot stronger. The L5 remained in service in the Australian Army in only a few regiments as a rapid deployment gun (4 Field and 5/11 Field Regts from memory). The Hamel project for local build of the British 105mm Light Gun was to be the primary field gun and replaced the L5 and M2A2 (though a few reserve units kept the M2A2).

As a direct support weapon the L5 could easily be replaced by a heavy 120mm mortar. Which would have a range of advantages if not the direct fire capability. Not least of all ease of loading compared to the trash compactor style spring loaded dropping breech of the L5 which was a really fearsome thing to stick your hand inside loading a shell. Which I only did a few times for familiarisation and much respect to the gun bunny’s who did it day in and day out with a maniacal gun ranging number hovering over the breech lever while your hand was inside it…

 

[STURM]

Yes I have personal experience of the L5 pack howitzer which was the British version of the Model 56.

Thank you for your feedback, it was very interesting and helpful.

The range of the L5 on full charge was only about 10 km.

Apart from HE, smoke and illum, where there any other rounds?

The big problem the Australian Army had with the L5 was its lack of robustness meant it could not provide sustained fire support.

I would guess that during the Confrontation, the lack of robustness was not an issue, as the guns were mostly deployed in static positions along the Indonesian border and didn't have to be moved around much.

As a direct support weapon the L5 could easily be replaced by a heavy 120mm mortar.

What in your opinion, would be the disadvantages of replacing a 105mm gun with a 120mm mortar? The Malaysian army's 10th Para Brigade has seriously looked at replacing its Model 56s with a towed 120mm but other units like the Royal Marines I believe have no immediate plans to replace their Light Guns. Italy's Alpini used to operate the Model 56 but I'm not sure if this is still the case.

A lot will depend on operational requirements, the threat and the terrain but the cheapest solution would be to go for something like the Thomson Brandt 120mm or the Super Rapid Advanced Mortar [SRAAM]. A problem with the Thomson Brandt - apart from its weight - is that crews will require steps to load it, due to barrel height. A solution that is more expensive but also one that offers mobility and crew protection will be mounting the mortar on an APC, either on a turntable or in a turret [like AMOS]. Another plus factor is the availibility of smart rounds for the 120mm mortar.

What were the main differences between the Oto Melara Midel 56 and the British L5 version?

 

[Abraham Gubler]

Apart from HE, smoke and illum, where there any other rounds?

L5 fired US 105mm M1 ammunition. So all the standard rounds. Australian Army added WP and SPLINTEX to that list above.

I would guess that during the Confrontation, the lack of robustness was not an issue, as the guns were mostly deployed in static positions along the Indonesian border and didn't have to be moved around much.

In VietNam the issue with robustness was not in movements. But in sustained fires. Shooting 200+ rounds a day, every day. In Borneo there were nowhere near this level of combat intensity so the L5s were never pushed to the same extremes. But in VietNam they started to fall apart.

What in your opinion, would be the disadvantages of replacing a 105mm gun with a 120mm mortar? The Malaysian army's 10th Para Brigade has seriously looked at replacing its Model 56s with a towed 120mm but other units like the Royal Marines I believe have no immediate plans to replace their Light Guns. Italy's Alpini used to operate the Model 56 but I'm not sure if this is still the case.

The Light Gun and the L5 are extremely different weapons. The L118 Light Gun in UK service doesn’t even fire the same ammo. As I said before a 120mm mortar can replace the 105mm L5 but not the 105mm L118.

A lot will depend on operational requirements, the threat and the terrain but the cheapest solution would be to go for something like the Thomson Brandt 120mm or the Super Rapid Advanced Mortar [SRAAM]. A problem with the Thomson Brandt - apart from its weight - is that crews will require steps to load it, due to barrel height. A solution that is more expensive but also one that offers mobility and crew protection will be mounting the mortar on an APC, either on a turntable or in a turret [like AMOS]. Another plus factor is the availibility of smart rounds for the 120mm mortar.

You don’t need steeps to load a long barrel mortar like the TB rifled 120mm. This type of mortar and most heavy mortars like 120 and 160mm don’t have a fixed firing pin like on 81mm mortars. You drop the bomb down the tube and after it hits the bottom the gunner engages the firing mechanism. So to load a long barrel mortar the tube is depressed to a shallow angle so the loaded can put the bomb in the tube then it is elevated to appropriate firing angle and the bomb slides down the tube. Then it is manually fired.

Long barrel 120mm mortars even the smooth bore types can replace 105mm L5s because they are much lighter and have less crew you can have more of them and closer to the enemy with the same resources. So this makes up for the2-4km range difference. Rifled 120mm mortars like the TB have almost the same indirect fire range. 120mm HE mortar bombs are in many ways better than 105mm HE. For anti personnel they are better but not anti armour but there are a few 120mm PGMs available now for anti armour.

What were the main differences between the Oto Melara Midel 56 and the British L5 version?

The L5 had English tags and the Royal Cypher on the ordnance. The L5s were all made in Italy right beside the Model 56s. There may have been some minor differences but nothing performance wise.