Interurban multiple unit (Queensland Rail)

Interurban Multiple Unit
IMU173 at Beenleigh in July 2012
Manufacturer	Walkers Limited Downer EDI Rail
Built at	Maryborough
Constructed	1996-1997 (100) 2001-2002 (120) 2008-2011 (160)
Number built	36 carriages (100) 12 carriages (120) 84 carriages (160)
Formation	3 carriage sets
Fleet numbers	101-110 (100) 121-124 (120) 161-188 (160)
Operator(s)	Queensland Rail
Specifications
Train length	72.4 m (237 ft 6 in)
Width	2.7 m (8 ft 10 in)
Height	3.9 m (12 ft 10 in)
Maximum speed	140 km/h (87 mph) (100 & 120) 130 km/h (81 mph) (160)
Weight	131.8 t (129.7 long tons; 145.3 short tons) (100) 130.4 t (128.3 long tons; 143.7 short tons) (120) 128.2 t (126.2 long tons; 141.3 short tons) (160)
Electric system(s)	25 kV AC overhead lines
Current collection method	Pantograph
Coupling system	Scharfenberg Type 10 coupler
Track gauge	1,067 mm (3 ft 6 in)

An interurban multiple unit (IMU) is a class of electric multiple units manufactured by Walkers Limited/Downer EDI Rail, Maryborough for Queensland Rail's Citytrain division between 1996 and 2011. The Interurban Multiple Unit is divided into in three subclasses, sets 101-110 as the 100 series, sets 121-124 as the 120 series, and sets 161-188, as the 160 series. The IMUs primarily operate services on Gold Coast and Airport lines, as well as some services on the Sunshine Coast line and peak hour suburban services.

The Interurban Multiple Units are essentially a three-carriage long distance version of the Suburban Multiple Units. Internally, the IMUs differ from the SMUs, being fitted with larger seats, luggage racks and mobility-access toilets. Like most trains in the Citytrain fleet, two three-car IMUs can be coupled to form one six-car set.

To provide rolling stock for the new Gold Coast line to Helensvale, in 1993 a contract for four 100 class sets was awarded to Walkers Limited, Maryborough. The first four IMU100s, 101 to 104 entered service in 1996 before the opening of the new line. As these were never going to be adequate to operate all services on the line, in July 1995 a further six were ordered. They were delivered in 1997.

In 1999 four 120 series sets were ordered for the Airtrain line to Brisbane Airport.

These are fitted with high-backed seats, one toilet per unit and luggage racks in different configurations. The 100 series and 120 series are interoperable, and operate together in