The German company Schöller special machines GmbH & Co. KG (SSM) has developed a new tunnel excavator based on a Volvo excavator. This excavator is suitable, with its size of about 16–18 tonnes operating weight, above all for small to medium cross passages in tunnel building. It is the first of its type since it is not available from Volvo in this form.
The company SSM was founded in 2014 and produces construction machines for special applications. Thanks to their employees, SSM possesses long years of experience in the building of specialised machines and offers a wide range of used and new machines for tunnelling and specialised civil engineering, for sale or also for hire. The main markets of the company are Germany, Austria and Switzerland, and also Norway, India and the USA. In order to increase the brand awareness of SSM in connection with Volvo worldwide, the new excavator is to be marketed in close collaboration with Volvo dealers.
First Tunnel Excavator is already in Use
For the new tunnel excavator, a Volvo ECR145E has been appropriately reinforced and rebuilt, and with its operating weight of about 16–18 tonnes is unique on the market. In contrast to other tunnel excavators, the SSM machine can also be converted back from the tunnel version to the original excavator model.
Thanks to the special processing and the hydraulic cylinder specially made for the SSM machines, this tunnel excavator features a longer lifetime. Particular the piston rod can cope with the special loading that only occurs in tunnel excavation work with a reduced risk of breakage. They are also protected against corrosion from the damp climate often found in tunnels. Last but not least, special bearing mountings provide improved stability. The equipment includes protection measures for the support blade, reinforced chain lead off protection and impact protection as well as a fire extinguishing system.
The first machine has been at work since March 2018 in the Albvorland Tunnel on the new line from Wendlingen to Ulm, and two further machines have been in use since summer 2018 in the Albaufstieg Tunnel in Aichelberg. The fourth machine is currently being converted and will probably be delivered to Switzerland, with SSM cooperating closely with the experts of Robert Aebi AG.
Larger Variants planned
Quite special requirements are posed for tunnel excavators in particular and they have to be equipped to cope with a wide range of conditions like various rock strata, water ingress, gases and vibration. Therefore the tunnel excavators are appropriately strengthened and protected. Larger variants of the tunnel excavator with operating weights between 26 and 40 tonnes are already planned. These will be based on the Volvo machines ECR235 and 355ENL.