Today we will be taking a look at yet another interesting adaptation of the Sherman tank, the L-33 Ro’em self-propelled howitzer. This machine was basically a large box placed on top of a Sherman lower hull, surrounding a 155 mm howitzer, with a Cummins V8 diesel engine providing the power.
Take a guess at which nation assembled this Frankenstein’s monster… did you guess Israel? Well done! You can now brag to your friends, who will certainly respect your knowledge on abstract Sherman variants.
The L-33 Ro’em (‘Thunder Maker) is one of Israel’s many machines built onto the Sherman, but with its enormous overhanging superstructure it is also one of the most extreme.
This large, boxy vehicle had some mobility issues, and it stood out on the mostly flat battlegrounds of the Middle East. As such, it was quickly replaced when more modern SPGs became available to the Israel Defense Force (IDF). While the L-33 was only in service for a relatively short time, it still served in the Yom Kippur War and the 1982 Lebanon war.
Israel is a nation that has enthusiastically embraced the idea that if you need a problem solving, the Sherman chassis is probably a good place to start. Although this has not been out of choice, as no military browses the tank market and says “show me the worst, most obsolete models ya got!” if they don’t need to.
From the first moment of its existence, Israel has fielded armed forces equipped mostly on an improvised basis. Necessity has been the catalyst for much of this adaptation, innovation and experimentation, as the very survival of the nation depended on it.
The Sherman tank has been at the core of this, where its functionality, practicality and adaptability enabled Israel to push the chassis to its limits decades after it first entered service.
Perhaps the most well known examples of modified Shermans was the M50 and M51 Shermans (often erroneously known as the “Super Sherman”) , in which Israeli industry (with France’s help) fitted a new power plant and 75 and 105 mm guns to the venerable Sherman chassis, breathing new life and capability into the 1940s tank.
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In the post Second World War period Israel had originally wanted to purchase new American and British tanks – such as the M47 and Centurion – but due to a number of reasons this was not possible. As a result, they gathered Sherman tanks from a variety of different nations.
These vehicles were modified, upgraded and adapted to suit Israel’s exact needs. These included designs such as the Sherman ambulance, Eyal observation tank, MAR-290 MLRS system, and recovery vehicles.
In the late 1960s a design program for yet another indigenously-produced Sherman-based vehicle was initiated, this time to create a self-propelled howitzer. This would be eventuated as the L-33 Ro’em, the focus of this article.
The L-33 saw an M-68 155 mm 33 calibre howitzer being mated with a Sherman chassis. To reduce complexity and simplify the manufacturing process, it was decided that the platform would not be fitted with a revolving turret, but a fixed armoured casemate instead. As the M-68 had a limited traverse, the entire vehicle would sometimes have to be moved bring targets under fire.
The L-33 was only manufactured as a base model with no variants. The exact amount is unknown, although some sources state a figure as high as 200.
It is not clear whether the L-33 was built onto M50/M51 hulls, or original hulls used explicitly for it.
A further development of the basic design equipped with a 39 calibre 155 mm cannon was studied, but no further development on the upgraded version occurred. Another example was fitted with a Soviet ML-20 152 mm howitzer.
The IDF realised the L-33 had several drawbacks stemming from the adaptation of the Sherman chassis for the design, along with the large silhouette of the massive casemate structure housing the gun.
In addition, even though it was fitted with a 460 hp diesel engine, the Sherman chassis was underpowered when used as the base for such a large self-propelled gun.
However, as the L-33 was only envisaged as a stop-gap project until new SPGs were introduced into service, and Israel’s general military superiority in the region, the IDF were able to operate the L-33 successfully in combat.
The L-33 Ro’em
The L-33 was one of the largest armoured fighting vehicles which used the Sherman body as its base. Similarly, the weight of the L-33 at 41.5 tons was considerably heavier than even the M51’s weight of 34 tons.
The Ro’em had a height of 3.5 metres, a width of 3.5 metres and a length (hull only) of 6.5 metres. When the main gun was secured for travel on the vehicle hull, the L-33 had a total length of 8.5 metres.
Its armored casemate was so large that it actually protruded out over the differential housing of the Sherman, creating a rather unusual “stacked” appearance.
The L-33 was fitted with a 15.5 litre (950 cu in) Cummins VT8-460 diesel engine, which developed 460 brake horse power at 2600 rpm. This engine was also used in the M50, M51 and other Israeli Sherman variants. The gearbox had five forward and one reverse gear, producing a top road speed of around 22 mph (36 km/h), and a range of 160 miles (260 km) on hard surfaces.
The main armament of the Ro’em was the Soltam Systems 33 calibre 155 mm howitzer, which was mounted in a semi-traversable mounting within an armoured casemate that sheltered the gun crew from small arms fire and shell splinters. The gun has a limited traverse of 30 degrees off centre each side, and an elevation range of +52 to -4 degrees. The welded steel structure of the casemate was provided with access doors on the sides and rear, as well as roof hatches for the commander and other crew members.
The 155 mm cannon was supplied with sixty rounds of ammunition, of which fifteen were carried in the fighting compartment for immediate use. The maximum rate of fire was six rounds per minute, but this could be maintained for short periods only, and the sustained rate of fire was two rounds per minute.
The gun could fire smoke, high-explosive, illumination and anti-personnel rounds out to a maximum range of 13 miles (21 km), and used Israeli-made ammunition as well as being capable of firing all standard NATO 155 mm munitions.
The ammunition was of separate projectile and powder charge type, which meant that the L-33 needed a large crew of eight personnel; commander, driver, gunner and five loaders.
The commander’s hatch was provided with a gun ring on which the secondary armament of the vehicle was fitted for anti-air or close-in defence; either an M-2 Browning .50 calibre heavy machine gun, or FN-MAG 7.62 mm machine gun. Only the vehicle driver had night vision capabilities, and there are no Nuclear/Biological/Chemical (NBC) protections system, smoke grenade dischargers or fire extinguishing systems fitted.
The L-33 was gradually introduced into service with the Israeli Defence Force from the early 1970s, and the platform was used to equip a number of artillery battalions serving throughout the country. The Ro’em had barely been fully introduced into service when its first major use took place. With very little warning the L-33 found itself taking part in the savage fighting of the Yom Kippur War of 1973.
The relatively easy defeat of Arab ground and air forces in 1948, 1956 and especially during the Six-Day War of 1967 had produced a dangerous level of complacency in the Israeli General Staff’s regard for Arab military capabilities. A new Arab coalition was forged determined to avenge past military humiliations, and their preparations for a combined offensive had progressed to final completion with the IDF and Israeli intelligence completely in ignorance about Arab plans.
October 6th 1973, was Yom Kippur, the holiest day in the Jewish calendar and large numbers of IDF personnel were on holiday when the Arab forces struck swiftly and decisively.
With the Syrian Army savagely assaulting the Golan Heights, and the Egyptian Army making a very successful breach of Israeli defences on the Sinai Peninsula the situation initially looked very bleak for the IDF, to the point that the General Staff considered the employment of Israeli nuclear weapons on their own soil, before the situation stabilised somewhat.
With all resources desperately needed to hold back Arab spearheads, the Ro’em found itself deployed to both areas of fighting.
The L-33 artillery battalions found much use when the IDF commenced counter-attacking Arab territorial seizures on both fronts. The Golan Heights were swiftly captured and the Syrian Army bundled out, but the situation in the south was far more complex. Stubborn Egyptian resistance meant that the Israeli assault was initially stymied, but a reorganised IDF force, aided by L-33 SPGs, managed to surround the major Egyptian formation.
However the international community intervened at this point and a cease-fire and eventual truce was organised, and the fighting ceased.
The L-33 had performed surprisingly well in such desperate circumstances, but many deficiencies had been noted in combat use. The very dimensions of the casemate meant that the vehicle presented a large target to any hostile gunner, and its size/weight and overhang meant that care had to be taken when driving in some terrain as the Ro’em was capable of tipping over at extreme angles.
The engine was also underpowered for the total mass of the platform, and the L-33 found it very difficult to keep up with fast-moving Israeli armoured formations.
Despite these deficiencies the platform soldiered on in IDF service for the rest of the 1970s, and found itself in combat again during the Lebanon War of 1982. Soon after this the excellent American M-109 155 mm self-propelled howitzer was introduced into IDF service, and the L-33 was quickly relegated to reserve use before being retired by the IDF.
In its short history the Israeli Defence Force boasts a magnificent record, under operational conditions that could sometimes accurately be labelled as desperate. To counter their small numbers the IDF makes the effective use of combat systems of all types a centre point of their war-fighting strategy, regardless of complexity or cost.
From 1948 onwards the IDF has shown itself to be happy using combat platforms in a variety of different ways, or adapting them for new purposes. The adoption of the Sherman tank chassis to manufacture SPHs like the L-33 Ro’em is a good example of this.
The L-33 was not the most successful self-propelled howitzer ever introduced into service, but needs must when strategic circumstances dictate, and the Ro’em performed well enough in the desperate days of the Yom Kippur War.
Only ever a stopgap program, the L-33 Ro’em stands as an interesting signpost on the road of self-propelled artillery development and history.