Electricity and automation – Mobile machinery and special vehicles

Mechanical, automation and electrical design are core competences at Comatec. In the design of mobile machinery, special vehicles and rail rolling stock these are inseparably linked. No mobile machine or train can move without careful electrical and automation design. Janne Hirvonen has worked at Comatec for six years now and started his new duties as business unit manager at the Electricity and Automation unit in the middle of September. Chief design engineer Juha Siekkinen and special design engineer Kai Aarikka work in his department. Comatec Group has 70 electrical and automation engineers and 25 of these work with mobile machinery.

Expertise in the design of mobile machinery, special vehicles and rail rolling stock has become a real strongpoint for Comatec. Comatec designs all aspects of mobile machinery, such as steel structures, transmissions, actuators, hydraulics, cabins, electrification, automation and software. In the Mobile Machinery and Special Vehicles business segment, electricity and automation are smoothly integrated with in-depth knowhow in mechanical design.

“Electrical engineering involves designing equipment and its wiring. On top of this we work on automation and programming. It is difficult to draw a clear line between these,” says business unit manager Janne Hirvonen.

Customer is number one

“In my department we carry out electrical and automation design, programming and testing for many different customers,” says Janne Hirvonen.

“Special design engineer Kai Aarikka, who designs automation software, and chief design engineer Juha Siekkinen, who mainly designs electrical systems, have carried out a wide range of different projects for many customers,” states Janne.

“The starting point for what we design and the way we design it is always the customer’s specifications. Some customers give very precise specifications for the design, others just give an idea of how the end product should function. On the basis of the source information, we start to design a system, we choose components, make circuit diagrams and in many cases wiring set drawings, and production drawings for a machine.

“For an automation system we design the necessary functions and the cabling between the actuators on mobile machinery and the automation system. Systems can vary in size from just a few signals to several thousand signals.

“We design electrical and control systems for mobile machinery, which typically include hydraulics, electric drives and a diesel engine. For control systems we design the display screens, the programmable logic, the buses and peripheral devices,” says Janne.

“We also take part in project and installation supervision as well as in choosing components and equipment, in competitive tendering, and in purchasing activities,” adds Janne.

“We carry out design work in different areas, such as remote access and production test equipment, according to customer requirements. If a customer wants this, we can add a risk analysis of machine safety to the design. We work with Comatec experts in different fields,” says Janne.

Kai Aarikka has most recently worked with the Rolling Stock unit on automation design for a VR (Finnish Railways) locomotive.

“This VR project is for a wagon gritter. Pipes run from the locomotive to the bogie wheels. The equipment we are designing heats the pipes and measures the temperature. It stops the grit from freezing in winter,” says Janne.

Kai Aarikka has also taken part in designing the automation system for the prototype machine for installing Posiva’s bentonite buffer blocks. Juha Siekkinen carried out the electrical design for the machine. Altogether some 30 Comatec experts participated in the design of the prototype. All areas of Comatec knowhow were required in the design, such as mechanics, hydraulics, electrical and automation knowhow and expert services. The hydraulics in the machine were replaced with electrical actuators and it will be remotely operated.

“The Posiva project has been the biggest project that I have been involved in at Comatec,” states Juha Siekkinen.

“I have also done some electrical design work for Sandvik, mainly for test equipment and prototype projects. I have designed raise borers and mobile drilling equipment for TRB-Raise Borers. I have also designed electrical systems for AW-Energy, working with our motion control team.”

“I have also produced some safety reports,” says Juha.

Machine safety

Machine safety is an integral element in the design of mobile machinery. The EU’s Machinery Directive affects every aspect of their design – including electrical and automation design.

“The standards and risk analysis set certain performance requirements for control systems. The performance calculations that I have carried out are one part of this work,” says Juha.

Design programs

“We have a wide range of design programs in use. The program we use depends on the format of the material that we receive from the customer, which has often been saved in a specific program. So the customer has a big say in the choice of the program we use,” says Janne.

“All our designers are not experts in all the programs. Designers are chosen for a project on the basis of who has the appropriate skills and knowhow for a particular job.


Kai Aarikka designs automation systems. Most of his work takes place at his desk, but some of it is in the field. Machines are tested in operation and modifications are made to them during testing.

“Testing always involves complete mobile machines. We carry out two forms of testing, either testing software code against a simulator or testing the operation of a finished machine,” explains Janne.

“In simulator testing we test different parts of the software and check if they function as specified. In a test the simulator models the machine and uses real controllers and control units.

“If there are faults in the way a system operates, we find out where they are. Anything is possible. The fault can be in many places, in the software, in components, in the drawings or in the manufacturing of the machine. If the fault is not in the software, it is probably in a component or in the wiring,” states Janne.

Commissioning support

“Commissioning takes place when all the equipment is ready for the first start up. Every now and then problems and new issues come to light during the first start up, and we can then give immediate assistance on the spot,” says Janne.

“We offer our expertise for the commissioning. If we have programmed a piece of equipment, the programmer goes to the site to provide commissioning support. He can make any necessary corrections and ramp ups on site”.

Many different projects

Juha, Kai and Janne like being able to work on many kinds of projects at Comatec.

“Almost every project involves something new. Nothing similar has been done before. It is interesting to examine the source data for a project and then plan how to get the best end result for what the customer wants,” says Janne.

“In my previous job I made slightly different variations on the same theme and in five years I had learnt what I was doing by heart. Here there is no fear of learning everything about the machines by heart. In the long run that is a good thing,” states Juha.

“Comatec’s flexibility concerning working hours and holidays is something that we appreciate highly,” say Juha and Kai.

“Flexibility does also depend on the customer. But I have managed to come to flexible arrangements with customers as well concerning holidays,” says Kai.