Sneak peek at a metro worksite: installation of standby generators

Haulage of the first standby generators to the metro stations of the Matinkylä–Kivenlahti section has begun. The first standby generator was hauled to the Kaitaa station on Tuesday, 25 February, and the second one to the Espoonlahti station at the end of the same week. Here we take a look at the haulage of Espoonlahti’s standby generator. 

Every new metro station as well as the Sammalvuori depot will receive a standby generator. A total of six standby generators will be installed in the Matinkylä–Kivenlahti section. The standby generator will start up automatically after a few seconds if the transformers serving the station’s HVAC and electricity lose power due to a defect or, for instance, a nationwide power outage. The standby generators have a rated power of 500 kilowatts. This capacity is sufficient to maintain the key safety functions of a metro station, such as lighting, the PA system, the evacuation elevator and access control. The standby generator ensures the metro station’s safe operation in the event of a power outage and people’s safe exit from the station. The supplier of the standby generators for Länsimetro’s Matinkylä–Kivenlahti section is the Geneset consortium – Geneset Powerplants Oy and Hautalan Sähkömoottori Oy.

Before the standby generators are delivered for installation in the new metro stations, the operation of the overall machinery is inspected in a Factory Acceptance Test (FAT test).

We previously had a sneak peek at how the escalators are installed (in Finnish)– for commuters, escalators are a visible and familiar part of metro stations. Standby generators, on the other hand, are placed out of commuters’ sight. The spaces that are visible to commuters, such as the metro platform and escalators, only make up about one third of all of a metro station’s premises: two thirds are hidden from view.

The size of the standby generator is approximately 3.9 metres X 1.6 metres X 2.6 metres (length x width x height), and it weighs some 4,500 kilograms. The standby generator ensures the metro station’s safe operation in the event of a power outage and people’s safe exit from the station.

The standby generator is brought underground in one piece – unlike, e.g., escalators, which are brought underground in multiple pieces and then assembled. The standby generator is delivered through the service tunnel and the future rail line to the vicinity of the installation spot, from where it is lifted into place using lifting equipment. Once in its final place, the protective plastic is removed from the generator and it is set up for operation.

The installation of standby generators is one of 30 subcontracts that are carried out on the entire rail line. Others are escalators, elevators, smoke extraction fans and camera surveillance, to name a few.