On Saturday 14 December 2024, Train World is running a farewell tour for the NMBS /SNCB Classical Twin EMUs, as Wikipedia calls the AM66 or MR66. Train staff call these Klassiekjes or Classiques. Sometimes in French Doubles. The farewell tour is sold out.
“After 85 years of good and faithful service in the railway landscape, the last railcars will be taken out of service in December of this year. The end of an era for many”, Train World says.
“We are saying goodbye to railcars that everyone (or almost) knows. The first 2-part railcar 001 dates from 1939 – and the last 782 delivered in 1980. In other words, 42 years of evolution of the same type of train!”
“Of the approximately 400 railcars that have ever operated on our network, only ten are currently still active. They will now be definitively taken out of service. Train World will receive one of those railcars, namely the 660, for conservation. So that this pearl of our railway history may leave the track, but not our heritage. She will also be part of the journey on 14 December.”

The Classical Twin EMU
The Classical Twin EMU unit is a series of electric train sets from the NMBS / SNCB. In the period 1939-1979, almost 500 of these train sets were built. Different sources name different numbers.
The first sets were originally delivered in two shades of green. From set 035 onwards, the dark green colour was the standard for many years, first with narrow visibility stripes and later with wide visibility stripes. Sets 001 to 034 also received the dark green paintwork. This gave this type of rolling stock the nickname ‘Groentjes‘ or ‘Greens‘. The term ‘Tweetjes‘ (Doubles) was also common for these sets.
From 1984 onwards, sets with number 152 and higher were painted burgundy red. The train sets from the MS56 or MR56 series are constructed from stainless steel and are never completely painted. MS in Dutch refers to motorstel, unit with drive wheels. Nowadays MR or motorrrijtuig is the official terminology. The French equivalent is AM or automotrice.
Most of the twin units were built by La Brugeoise et Nivelles, Bruges (now Bombardier) and have an electrical installation by ACEC in Charleroi (now Alstom).
Six sets were built in 1970 for Sabena, now Brussels Airlines, to use on the then newly electrified Brussels – Brussels Airport line.
15 sets from the MS54 series were converted into postal trains for De Post / La Poste, now Bpost, in 1988.


Personal history with the twin units
When I started as a train guard at NMBS / SNCB in 2012, the twin units were very present. The burgundy liveried units were never modernised and didn’t feature any broadcasting system.
We used them on on omnibus services from Antwerp to Nivelles, sometime three, four or even five twin sets coupled to each other. While we couldn’t make announcements, people seldom missed their stop. People were more self-reliant in 2012.
I don’t remember when was the last time I rode on a Klassiekje. It must have been on the Antwerp – Turnhout route. I always hoped first class was on the Antwerp-Central side, so I could legitimately go to the front and film our arrival into our railway cathedral.
Klassiekjes are / were simple and devoid of computers. So they are / were reliable. But obviously their height, their systems are outdated.
Technical specifications
The trainsets have an axle arrangement (A1)(1A) + (A1)(1A) and are driven by four electric motors (one in each bogie). From MR66 onwards, the rolling stock has a maximum speed of 140 km/h (previously 130 km/h) and the double-leg pantograph was replaced by a single-leg pantograph.
In the MS70JH series and earlier, the traction motors are controlled by driving resistors and a Jeumont-Heidmann switching roller (hence: JH).




Germany
From series MS70TH (number 665 and higher), the traction motors are controlled by thyristor choppers from ACEC Charleroi. The series with choppers are not permitted in Germany. For the L-09 / 5000 service, the German overhead line up to Aachen Hbf carries 3000 V DC (as in Belgium), while in the rest of Germany 15 kV AC is used.
The classic motor units can be coupled in multiple units with the MR75 ‘Pig Nose’, which is also equipped with a semi-automatic Atlas-Henricot coupling. MR75 units are technically two twins scotched together to form a quadruple unit.

Netherlands
The train units are built for use on 3000 volts DC. Because only 1500 volts are used on the Dutch network, these units can also operate in the Netherlands, albeit at half power. This allows the trains to be used for the L-train services to the Netherlands, although this option was only used on the Liège-Guillemins – Maastricht line in 2012. At the end of 2012, the train units on this route were replaced by the MR80 ‘Break’. The MR80 signified a break with the past, hence the name.
On Line 12 Antwerp – Roosendaal, the current units only operate in the event of a unit from the MR75 series failing, and then the train is limited to Essen due to problems with the clearance profile at the Roosendaal platforms. The 001 to 049, which were much higher, were able to reach Roosendaal without any problems.
Inside
In March 2024 railway journalist Herman Welter told VRT NWS: “They look very old-fashioned, but are actually very solid. What is striking: the benches have five seats in width, two plus three. Now, in practice, that is actually only one and a half and two and a half seats. In the past, people sat close together on the train. But now they have backpacks and laptops with them and they no longer fit two on that small bench, let alone three.”
In first class, the layout is 2+2.
Due to its age, this rolling stock does not have modern comforts such as air conditioning or a closed toilet system. However, these trains do have an extensive heating system, which is located as a large block under the seats, so that they are still comfortably warm on cold winter days, unlike other trains.






Modernisation
Since 1999, the MS66 to 74 series have been modernised and painted in the NMBS New Look very light grey livery. The interior was also rebuilt from scratch.
A number of classic sets were also modernised and adapted to CityRail sets that later also served on the Regional Express Network (GEN or RER). These sets are similar to the other modernised sets, with the exception of electronic announcers, compartments with standing places, a modified colour and some technical details (such as tail lights with LEDs and a static converter).
From 2019, these sets were stripped of their CityRail colours and converted back to the NMBS New Look colours.


Walk-through facility
Each classic motor set has an intercirculation door at the end, making it possible to walk from one train set to the other, as with the MR96. The train driver sits on the right in a small cubicle next to the walk-through head.
After two sets have been coupled, the passage is created by unlocking the end doors, folding out the footplates and placing the bellows against each other. When a set is not coupled, the doors at the ends are locked. Even when a motor set is coupled to MR75 (without walk-through facility), the walk-through head remains folded in and locked.
All motor sets have a luggage compartment behind the walk-through head at one end. In theory, all trains would be oriented in the same direction (with the baggage compartment on the south side on the Brussels North-South connection).
This would mean that a second-class compartment would always be coupled to a baggage compartment. Because the baggage compartment is not freely accessible to passengers, in theory they would never be able to use the walk-through facility.
In practice, however, it often happens that trains end up in the opposite direction after completing a certain route. Only if two coupled trains are facing each other with the second-class compartments facing each other, passengers can walk from one train to the other.
Deployment
In their early years, the classic multiple units operated all electric IC connections
where no pull-trains operated. With the arrival of the MR80 and later the MR96, the twin units were increasingly driven away from the IC and IR connections and were thus increasingly used as local services (L-train) and rush hour trains (P-train).
With the arrival of the MR08, the Siemens Desiro Main Line, they are also increasingly used less on the local omnibus trains. They could mainly be found on L-connections in Wallonia and the S-networks of Liège and Charleroi.

2024
In 2024, only the MS70JH (648, 660, and 663) and MSCRs (965, 988, 991, 997) will still be in operation. These units have all been modernised. The MS62s, MS63s, MS65s and MS70 Airports, which were not modernised, were taken out of service in 2012-2013. Since 2014-2015, modernised multiple units have also been taken out of service.
The 624 was taken out of service in early December 2023. This was also the last unit of the series built in 1966 that was in service.
The 624 and 660 are being preserved. On 6 February 2024, unit 731 was taken out of service as the last of the MS73 series.
In early January 2024, the 624 and 660 were put back into service due to a shortage of equipment. The 642 and 663 were also put back into service. On 6 March 2024, motor unit 624 was taken out of service again.
Italy
Some of the twin units, mainly units from series 54, 55 and 56, were sold to Italian private railway companies. As of 2024, the trains are no longer in active service there.
UPDATE 12 DECEMBER 2024 | A few left?
We’re hearing a few units will remain available for the train to Aachen, as the planned I11 coaches often have issues.

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