The Light Tank Project

The caption on this photo reads - "Eyal Himelstein and Nissim Ben-Hemo on the light tank prototype".

There's a lot of misinformation on this subject on the internet, as far as I've seen the photo traces to one book. There is little information on the tank itself in the book. I've translated the text in the hope that people could gather the facts for themselves instead of being confused by bad machine translations or the broken PDF file.

The entry is by Nissim Ben-Hemo in a book in memorial of Colonel Yehiam Harpaz, one of the leading officers in the Merkava development program and often called "Mr. Suspension". He was the inventor of the Mark 3 suspension. The entry is focused on his role in the light tank project:

    "The development and assembly of a prototype for a light tank were carried out in parallel with the development of the Merkava Mark 4. The technical branches were very busy with the many new assemblies that were introduced with the Mk.4 tank. In contrast, the automotive aspect didn't need much intensive development work as the suspension and powerpack were based on existing parts. For this reason, the head of MANTAK asked Yehiam to take on the light tank project. He told him the deadline is about 20 months from now. Yehiam responded that he couldn't see a reason for the project to take longer than 8-9 months. The following week the head of MANTAK informed Yehiam that he made promises to all the relevant officials that the project would be done in no longer than 10 months.

    Yehiam laughed “I didn't mean for that...10 months is between us…” but he acknowledged the facts, and committed to the task and dense schedule. In certain phases, the project was headed by the CO of the suspension branch, Eyal Himelstein, but as the project entered higher gear Yehiam took the lead.

    Yehiam saw an opportunity to trial and progress future light AFV solutions (as is nowadays, more than a decade later, the trend of future AFV development seems to be going) and wasn’t tempted by the convenient solution of basing on the Merkava suspension hubs. The solution was based on torsion bars, even though the automotive branch had no prior experience in this type of suspension. The engine used was the Achzarit’s engine, which was too big and the tank had crazy airflows inside. The radiator of the Achzarit’s engine is huge and didn’t fit in its natural place next to the engine, but a particularly creative and bold solution of putting it under the fighting compartment was made.

    Yehiam met with officials of the Ashot-Ashkelon company and asked for their help in advancing the project with machining and integration. The company presented the financial meaning and when Yehiam responded he couldn't measure up to the required sum the company agreed to assist anyway out of personal respect for Yehiam and an understanding of the project's significance.

    The project’s period was characterized by an intensity we didn't have alike beforehand. For several months the branch’s personnel and workers labored around the tank in MSA as if they were a hard-working bee swarm. The typical image is Yehiam working on installing components inside the tank and the workers receiving instructions, acquiring and making parts as needed. During the last preparations weeks of the tank, the workload, and pressure rose to an all-time high, lest we talk about the final days, in which we didn’t rest for a minute. Every problem or deficiency received immediate response and no effort was spared. Yehiam managed the team with intensity and on the day the preparations were completed we finished a task that in normal conditions would stretch a whole week. At the end of that day, the tank was displayed to the head of MANTAK who admired the result and the impressive achievement of the schedule we kept on. Yehiam gave credit to the team and emphasized the hard work of all the branch personnel.

    The following day we were astonished to find that Yehiam had taken a 2-week vacation abroad with his family. The surprise was major and with it, the realization that Yehiam didn’t share with us the immense pressure he was under due to his familial obligations, while he rose to the challenge of completing the job in what was the 90th minute for him. Yehiam succeeded in bringing the project to a level of maturity that left none of us to deal with open issues. During the two weeks that Yehiam was abroad, almost no work was carried out on the project, until the trials started.

 The trials were set to be conducted in NSA in the Palmahim base, but the progression rate was jarring for Yehiam. The safety regulations and the short days broke his patience. I remember the conversation when Yehiam expressed to the commander of the NSA his anger and disappointment in the cooperation and the way the trials were being conducted. Yehiam simply informed to NSA’s commander that he was taking the tank to Golan Heights (“My testing site!”) and continuing the trials exactly how he understood and saw fit. And so happened, the tank was moved to camp Yarden.

    A special incident I remember from the course of the trials was when the turret got dislodged out of its position and a problem arose with its mating to the hull. The turret branch’s commander arrived on site to check if continuing the drive was possible and determined, rightfully, that in such conditions driving should not be allowed and the tank should be returned to MSA for repairs. Yehiam knew that doing so would lead to an enormous delay in the trials and took liability for continuing the trials on himself. Where the solution he decided on to fixing the turret was tying it down to the hull using metal chains… Few officers would have the guts to resume trials in such conditions. The trials were completed with full success and in an unimaginable schedule - Only 7 months from the day the task was given to the successful completion of the trials".

Yehiam Harpaz is the second from the right. photo via https://yadlashiryon.com/