The first major milestone for the “New portable pump” project was the world’s leading trade fair, Interschutz 2015 in Hanover. The expectations from all sides were enormous, as after the presentation of the FOX III in 2005, it was widely assumed that a new Rosenbauer portable fire pump would be revealed at this trade fair, also. But nobody was ready for this portable fire pump – and getting there was not easy.

The landmark decision to use engines from BRP-Rotax for the new generation of portable fire pumps opened up many new possibilities. A major aspect in the decision-making process was that BRP-Rotax was the only manufacturer who could offer a product family in the performance range between approx. 30 kW and approx. 45 kW. So finally, a “genuine” PFPN 10-1000 could be built that would be lighter and less expensive than the larger equivalent. In addition, the design of the engines for use in snowmobiles and jet skis offered the perfect technical basis for a portable fire pump, as the engines are not just light and powerful, but also designed for maximum reliability and excellent starting behavior.

Test run at the test stand

Test run at the test stand

The biggest challenge for the small development team was to not just develop one portable fire pump, but in fact two, before Interschutz 2015. As the aim was to implement both pumps as structurally identical as possible. So especially in the construction phase, each step had to be carried out twice, in order to check, for example, whether the fuel tank, the arrangement of the cooling system, or the position of the priming pump was compatible with both engines. If you put both pumps side-by-side today, you can see how well this turned out, thanks to the meticulous work.
While there is a bit of free space under the hood of the FOX S, you quickly realize with the FOX 4 that the package was optimized down to the last detail. In parallel to the construction, the first practical tests were carried out with so-called mock-ups. With these mock-ups, the first engines were combined with the available pump parts, in order to gain experience for tuning the engine, perform temperature tests, and to be able to refine the design of the cooling system.


The first prototypes

It got really exciting when the very first prototypes of the new generation were built. For the first time, the newly developed pump part, the advanced priming pump, and the engine adapted for use by BRP-Rotax were all brought together. Supplemented by the cooling system, the new fuel system, a new exhaust developed from the ground up, and the LCS 2.0 control and instrument panel developed in parallel, the time had come to start up the new FOX S for the first time. A moment which is etched into our memories as a team.

Cold start test

Cold start test

Then extensive testing started with the first prototypes. Alongside numerous individual and system tests until the release of the individual component groups, such as exhaust, tank system, cooling system, and centrifugal pump, the greatest challenge was the so-called continuous operation. This relates to testing the service life, which represents the final criterion for releasing the pump. In this process, the pump is operated at maximum output for several hundred hours and/or operated at other operating points on the test rig, and all relevant data is continuously monitored.
Approval is only given when all relevant components have passed the full service-life test without any damage. And precisely this phase also showed the strength of the partnership between BRP-Rotax and Rosenbauer and the tremendous personal commitment of the team members. Because unexpected challenges can arise when you try to break new technical grounds. But what matters is how you react and fix them. And so, the challenges of the test phase were mastered in a joint effort and the technical approval was achieved.


Countdown to Interschutz

Interschutz - Rotax, Rosenbauer, Bosch Engineering

Discussion between experts from BRP-Rotax, Rosenbauer & Bosch Engineering

Now the focus was fully on Interschutz. Two variants of the devices were built by hand for the trade fair, in order to demonstrate the unique features of the new portable fire pump.
It was a big surprise to everyone when it was revealed during the press conference that, with the FOX S, a completely new portable fire pump had been added to the product range.
The new FOX S portable fire pump became the most visited exhibit at the Rosenbauer exhibition booth, along with the PANTHER and the Heros-titan. We were truly besieged by visitors and had countless positive discussions.

For the project team, Interschutz was an absolute highlight and left us with a sense that we had made many good decisions in the last few years. But a lot of work was waiting for us back at the office. After all, our customers were eager to know how the successor to the FOX III would look! But more about this in the next blog post.