DSB IC3 class MF

This page is dedicated to the IC3, in my opinion the best DMU on rails, at least until I experience the IC4..

Interior & Comfort
Pros & Cons
Variants
Technical Details
Specifications
Links

Overview

The design of the IC3 (InterCity 3-car) DMMU began in the mid-eighties as a replacement for the ageing "Sølvpil" (Silver Arrow) trains from 1963 consisting of 6 cars and 2 dieselhydraulic power cars, with the aim of attracting more passengers and working as an interrim solution while mainlines were electrified.
The principal lines of the Danish railways consist of a main line starting at the East coast and Copenhagen, going West across the islands of Sealand (with two side branches) and Funen and eventually branching in 5 directions towards different parts of the Jutland peninsula.
To make train travel more attractive, it was necessary to reduce the journey times and the number of changes, and to achieve this a DMU concept was chosen for the new trains. Apart from the ability to send different parts of the train in different directions at branch stations, DMUs would also achive this through better acceleration and higher speeds between the closely spaced stations with average distances of 30km (19miles) between stops. Furthermore the DMUs would ease shunting in connection with the ferry crossing between Funen and Sealand until the completion of the Storebælt (Big Belt) bridge/tunnel link. Rather uniquely at the time, mechanical transmission was chosen, as will be discussed further under technical details.
The train was introduced in 1990 and marked a return to the lyntog ("lightning train" or express train) design first introduced in 1935 - with 3 aluminium cars on shared bogies and an engineless middle car.
The core network was upgraded to take full advantage of the 180km/h (112mph) top service speed of the IC3 in 1997. Despite the nicknames such as "gummikys" (rubber kiss) and in Germany "Gumminase" (rubber nose) earned from the characteristic rubber coupling diaphragms, the train has been received well by passengers in Denmark and Germany and must be said to be one of the most successful Danish trains in terms of comfort and performance. IC3 services have been extended to the 2 other mainlines on Sealand, towards Kalundborg and Rødby. The train has also been exported to Israel and ran services in South West Sweden for a while until the lines in question were electrified.

Electrification has not proceeded as far as was originally hoped for, however, and the successor to the IC3, the IC4, will also be a DMMU. The IC3 sets are to undergo refurbishment to make them more suitable for assisting and replacing regional services run by locomotive-hauled coaches and MR DHMU train sets.

Interior & Comfort

With cars 3.1m wide the IC3 has room for very comfortable adjustable 2+2 seating. Most seats are arranged 2 by 2 around a table and aligned with the windows. Headphone sockets, air vents and lights are provided at all fixed seats. The comfort of the standard class interior is underlined by the fact that an IC3 set has only 16 first class seats out of 144 total. There is room for luggage between seat backs facing each other and on the overhead racks. There is also a flex area with foldable seats, which can accomodate wheelchairs or extra luggage.
The vestibules contain one accessible toilet (with powered doors) and one normal toilet as well as the train managers compartment and a small galley. Due to the relatively small train size, the galley does not work as a shop - hot food is ordered from the trolley service. While less relevant in our mobile age, there is also a payphone on board.
As part of the upcoming refurbishment for regional service, the galley and normal toilet will be removed to make room for additional seats and flexible area.
The trains feature 2-line information displays with estimated times of arrival for all stations and electronic car numbering & seat reservation systems, all of which can be updated en route.


2nd class interior.	Quiet area (2nd) and 1st class towards the end of the car.

Pictures by Bjarke Hvass, www.holbrook.dk.

Due to the low platforms in Denmark, the floor levels in trains are usually above the platform and entry steps are common in Danish trains. While the high floor level (and extra step compared to eg. the class MR DHMU) is less practical; especially for regional use, it would seem it gives room for good engine suspension and soundproofing. Furthermore the mechanical transmission allows the train to cruise at low engine rpm and load after acceleration is completed, altogether resulting in a very quiet interior for a high-performance DMU, even in the motor cars with 2 engines. This is complemented by a comfortable suspension.

Pros/Cons

High comfort levels & low noise level for a DMU
Good fuel economy, especially considering performance
Couples and runs in tandem with EMU version
Full throughfare through coupled units as well as full-width cabs
High acceleration

High floor
Few doors for regional services
4 engines per 3 (short) cars
High purchase price

Variants

An electric 4-car version, the IR4 (class ER) with the same top speed, was built and entered service in 1993. Opposite the IC3, the IR4 was originally intended for regional services, but the practicality of running this EMU in tandem with the IC3 on busy electrified stretches (see picture below) and then uncoupling the IC3 units towards different destinations on non-electrified lines resulted in the IR4 being put to good use in long-distance services. (Likewise, the excellent acceleration of the IC3 makes it capable of handling short-stop services too.) The original manufacturer of the IR4, Adtranz, has been bought by Bombardier and the IR4 design partly lives on in the form of the Contessa or "Øresundstog" (Øre Sound Train) running between Copenhagen/Sealand and Malmö/South Sweden via the new bridge link. The Contessa is a more traditional design with the same length, but featuring 3 longer narrower cars with 2 bogies each using a heavier steel construction instead. The foldable windscreen and drivers' seats and connecting rubber diaphragms were retained and on the positive side, the middle car was given a low-floor area and entrance.
A regional version, the (original) IC2, intended for use by private branchlines, was also subsequently designed.
Finally it is worth mentioning that the front and carbody design can be seen on Spanish and Belgian trains.

Technical Details

Powered axles	Engines, transmissions and exhausts	Air intake & filters
Diesel tanks	Compressors & alternators	Batteries & electrical equipment
Oil burners & compressed air tanks	Magnetic rail brakes

(I do not yet have information on the centre car underfloor layout.)

Apart from breaking with the DMU tradition of 1 engine per car, the IC3 has two engines in each of the front and rear cars. This helps balance the axle loads on the shared bogie design and also results in a completely engine-free and therefore very quiet middle car. Apart from this, in connection with the layout, it is worth noting the crumple zones of the door/vestibule areas and the somewhat unprotected location of the fuel tanks.
The IC3 is a 2nd generation DMMU using modern automatic transmissions and a startup torque converter. When starting, the transmissions are in 1st gear and the low-speed torque converter is used for smooth startup - effectively a hydraulic transmission mode. At a speed of approximately 35km/h (22mph), the torque converter is locked and the train proceeds in mechanical transmission mode up through the gears. Comparing with other trains it would seem the top speed is limited by the gear ratios in this case, which have been dictated by the linespeeds of up to 180km/h and the importance of acceleration to take advantage of these between the closely spaced stations in Denmark - the power to weight ratio is larger than dieselelectric trains with top speeds of 200km/h such as the Voyager series.
This, the direct drive and multiple gear ratios give the IC3 high acceleration capabilities - it was necessary to develop electronic engine torque capping to avoid wheels slipping and spinning in the lower gears. With overhauls every 600000km (373000miles), only 2 out of approx. 400 transmissions in service have been replaced over 15 years. The ability to isolate a traction group and continue on 3 engines also helps give the train a good degree of reliablilty.
The IC3 is especially well-designed for multiple unit use on branched lines. When coupling, the rubber diaphragm helps cushion the (low-speed) impact. The entire front, lights, windscreen wiper, driver's seat and controls swings to the side and stows away, combining a spacious cab and wide windscreen for the drivers with full passenger throughfare. The train sets are capable of uncoupling while driving, although this is not done in practice.

As seen on the pictures, the articulated design means the gaps between the cars can be made very small. This in turn gives the train good aerodynamic properties considering the flat nose, especially when running in multiple, where the diaphragms ensure a flush coupling between sets.
The streamlining, light weight and efficient transmission result in good fuel economy - approximately 10% better than a traditional dieselhydraulic 2-car train set with a top speed of 130km/h built in steel (the MR) and approximately 10% better than equivalent solutions with hydraulic or electric transmission according to DSB.
While DMUs are often criticised for their efficiency, DSB estimate the crossover point where their current (somewhat older) locomotive-hauled stock would be more efficient is at about 4 IC3 sets or 12 short cars or between 500 and 600 passengers. 4 IC3 sets would still have the advantage of higher acceleration, wider cars and more destinations. As mentioned, the IC3 can also couple and run in tandem with the IR4, its 4-car electrical sister design, making the most of the investment in partial electrification.

Designers	DSB (Danish state railway)
Built by	ABB Scandia/Adtranz (now owned by Bombardier) in Denmark, Duewag in Germany
Operators	DSB 1990-, RY 1992- (Israel) , Blekinge Läns Trafik 1990-2005, Kalmar and Östgöta Läns Trafik 1996-2005 (Sweden)
Dimensions	length 58.82m, width 3.10m, height 3.85m, floor height 1.30m
Weight	97 tonnes
Seating	Before refurbishment: 144 total arranged mainly 2+2, 16 1st class, 122 2nd class plus 6 folding. After refurbishment: Most seats are arranged two-and-two around a table and aligned with windows
Cars	MFA: motorcar with doors/vestibule, 20.54m Before refurbishment: toilet, pantry, 16 1st class seats, 22 2nd class seats After refurbishment: xx 1st class seats, xx 2nd class seats FF: unpowered middle car with 64 2nd class seats, 17.74m MFB: motorcar with doors/vestibule, 20.54m Before refurbishment: normal & accessible toilet, 36 2nd class seats + 6 folding seats After refurbishment: xx 2nd class seats
Engines	Before refurbishment: 4 x Deutz BFBL513CP 8-cylinder aircooled After refurbishment: 4 x Euro 3
Power	Before refurbishment: 4 x 294kW (1600hp) at 2300rpm After refurbishment: 4 x 331kW (1800hp) at xxxxrpm (although the torque properties are more important for mechanical transmissions.)
Transmission	Mechanical, before refurbishment: 4 x ZF Ecomat 5HP600 5-speed automatic transmission with lockable startup torque converter (0 to approx. 35km/h (22mph)). Gear ratios 1:2.803, 1:839, 1:1.364, 1:1, 1:0.799. After refurbishment: 4 x ZF AS-Tronic 12-speed automatic transmissions Reversing final drives. Axle arrangement: 1A' A1' 1A' A1'
Acceleration	Up to 1m/s/s although the full acceleration is rarely used in service
Maximum speed	180 km/h (112mph) in service, 200km/h (124mph) during testing
Braking	Before refurbishment: pneumatic disc brakes, magnetic (friction) rail brake for emergencies. 160km/h (99mph) to standstill within 1000m. After refurbishment:
Energy regeneration	During braking the transmissions remain engaged, driving alternators and compressors without extra fuel consumption according to www.railway-energy.org.
Fuel consumption	1km/l (2.35mpg), including shunting, idling, climate control and empty service runs
Multiple operation	Up to 5 train sets of type IC3 and/or IR4 (4-car EMU). Full passage through train possible through cabs with foldaway windscreens & driver's seats.

Links

The IC3 register at www.jernbanen.dk - in Danish, but press the little yellow boxes for pictures
DSBs IC3 page with specifications (in Danish)

Updated May 2007 by NSA. If you find an error or know more about the IC3, I would like to hear from you at