The BTS system has been provided with an initial fleet of 35 x 3-car trains supplied by Siemens
out of the SGP factory in Wien (Vienna), Austria. Train lengths can be increased to 6-car trains in the future.
A 3-car set is 65 m. long and comprises two driving motor cars (A cars) with traction equipment with a trailer car (the C
car) between them. When extended to 6 cars, two non-driving, motored cars (B cars) and another C car will be added.
The car body is constructed of spot welded stainless steel and is similar in design to the
cars supplied for the Taipei (Taiwan) metro system. The body shell exterior is painted in two layers of epoxy primer
and two finishing coats of acrylic, graffiti resistant paint. The cab ends are in Glass fibre Re-inforced Plastic (GRP).
The floor is built to a 45 minute fire resistance specification and is covered in hard wearing PVC with a blue or grey speckled
pattern to reduce dirt visibility. Car windows are tinted to reduce glare.
Wide end gangways are provided within each unit to assist in the circulation of passengers.
All seating is longitudinal and there is a large amount of available standing space. I never saw it all used.
Seats are in yellow GRP and are arranged in concave curved sets. At first I assumed this was to accommodate door engines
fitted on the floor behind the seats but the door operators are mounted in the ceiling. They are exposed to view from
the outside of the train when the doors are open. I wonder if this will lead to maintenance problems in the future.
I cannot see any reason for the curvature of the seats.
The interior panels are of GRP finish in a special graffiti resistant paint. Of course,
there is no graffiti on public transport in Thailand and very little anywhere else in the country.
Each car has four sets of bi-parting doorways, externally mounted. Electric door operators
have a threaded rotating shaft drive and these are mounted over the doorways. The glazing in the doors is in an unusual
design, presumably to reflect the direction of closing. Porsche Design was employed to assist in the system design.
The train control system has a door lock which activates with a loud "click" as the train starts. I also noticed an
emergency door opening device on each car. This, I was told, is activated by the driver in case of an emergency so that
passengers can escape. As there is no side walkway and only a low barrier along the outsides of the viaduct, I thought
this to be a somewhat unsafe practice. There is nothing to stop a person opening the door and falling 12 m. into the
street below. There is apparently, some internal debate as to how this should be used. End evacuation is the preferred
option for emergencies as trains are provided with end doors in the cabs and the centre of each track is reserved as a walkway.
A noticeable feature of train operation is the forward and aft rocking which occurs when the
train stops. This must be due to the suspension. However, the ride is generally very good. There is a certain
high level of low frequency noise which seems to come from the air conditioning pods mounted in the roof at each end of the
cars. This noise can be quite unpleasant at times. There is also a high frequency tone from the traction/braking
units, which appears to be electronically generated.
The traction equipment is Siemens IGBT 3-phase system driving 2 traction motors on each bogie.
There are two converter units on each motor car, one supplying two motors. The maximum tractive effort per motor is
250 kW or 230 kW continuous with a maximum speed of 3,600 rpm. Air controlled friction braking and dynamic braking is
provided on the motor cars with friction braking on the trailers cars. An automatic, spring applied parking brake is
also fitted. Friction braking is through wheel mounted discs. The control system provides for dynamic braking
at all times, with friction braking added on the trailer car if required. Full emergency capability is provided in the
friction brake system. The wheel slip control has speed sensors on all axles.
