A relatively rare heavy pump, rated at 2400 LPM at a time when almost all German pumps were rated at either 1600 or - in most volunteer fire companies - only 800 LPM. One reason these higher capacity pumps were not all that popular was that they were very often not able to be used to their full capacity because hydrant systems in many areas rarely supplied more than 2,000 litres each - and often quite a bit less. When this was built, if you wanted a beefy 250 BHP engine in your Mercedes to power your big pump, you had to buy a 16 ton chassis - even if you would only ever load it up to 12 or 13 tons.
So - this was how it turned out if you wanted a high capacity pump. Similar considerations led to the disappearance of heavy pumps in other countries, including Belgium where the medium pump became known as the "half heavy".
This was incidentally the same rationale behind Manchester buying D1617 pump appliances in the years before Ford SVO squeezed the Perkins 170 BHP V8 engine into the 1317, as it was the only version which had the more powerful motor.
So - this was how it turned out if you wanted a high capacity pump. Similar considerations led to the disappearance of heavy pumps in other countries, including Belgium where the medium pump became known as the "half heavy".
Added by Rob Johnson on 19 February 2021.