R.T.M. MABD 1801 'Sperwer' motor carriage

Please note: this page will be updated during the construction of the motor vehicle

R.T.M. MABD 1801 'Sperwer' was a railcar from 1925 with a diesel-mechanical drive, with the drive unit located in the luggage compartment and driving the inner axle via cardan shafts of both bogies.

The axle configuration of this was 1A'-A1'.
The 1801 was built by Linke-Hofmann in Breslau and put into service as R.T.M. 318, was renumbered after the war in 1946 to M 64, rebuilt in 1951 and renumbered to M 1701 and renumbered again in 1953, now to MABD 1801, where it was also given the bird name Sperwer (Sparrowhawk).
R.T.M. MABD 1801 'Sperwer' was withdrawn from service after a collision with a tanktruck and demolished in 1962.

Shortly before the invasion of 1940, Rotterdamsche Tramweg Maatschappij diesel tram No 318 prepares to leave Rosestraat in Rotterdam with a pair of bogie trailer carriages.

R.T.M. MAB 1701 on the 2e Rosestraat in Rotterdam, early 1950s, without the luggage compartment and without the bird name. (photographer n.a.)

RTM MABD 1801 Hellevoetsluis 21-07-1959.jpg

R.T.M. MABD 1801 'Sperwer' in Hellevoetsluis on July 21, 1959 (photo H.Ruitenbeek coll. J.J. Smit)

Construction started on November 14, 2023.
The railcar will be made entirely of plastic, this method is new in the workshop, although tests have already been carried out on the left and right.
The polystyrene plastic is much cheaper and easier to machine than brass.
Both the running bogie and the motor bogie were already in order and tested and can be mounted immediately.
Unlike all other equipment from the M.B.S. and R.T.M. the MABD 1801 is the first motor vehicle with axles on bearings.
This is not an unnecessary luxury, as the railcar has a fairly large weight mounted under the floor, because plastic is too light in itself to get sufficient adhesion to the track.
It will certainly benefit the driving characteristics.

The first photo of the plastic frame with the name and construction date, made of PVC laminate flooring.

Initially the wagon floor was too high for the superstructure, so recesses were made in which the bogies could rotate.

The minimum radius for the curves to be driven on is 1000mm (R2.5), anything smaller will inevitably lead to derailments.

An overview of the frame, with the bogies recessed into the frame.
If desired, the wagon floor could be lowered even further, but tests must first be carried out.

The completely overhauled NWSL motor truck which previously sat under the M 1806 and was in storage for more than 4 years.
The bogie sides have been reproduced from the drawing, with the current collection buses concealed behind them.
The smaller distance between the wheels and the underside of the wagon floor is clearly visible.

For this purpose, spacers have been placed between the subframe and the vehicle floor.

These 4.5mm high spacers lower the vehicle floor sufficiently to provide a visually propriate appearance.

Getting rid of it in the passenger compartment will now be quite a task.

The fact that these motor units are constructed so high is because the axle of the electric motor is fitted almost 11 mm higher than the wheel axles.

This powered bogie no longer had tilting shoulders, visible as the small white piece of plastic at the bottom of the subframe. the M6 nut., this was not necessary for the previous application in the M 1806 'Bergeend'.
These tilting shoulders give the motor truck the opportunity to tilt relative to the subframe.

Another overview of the frame, with the bogies recessed 9mm (double spacers) into the frame.

This again was brought back to 4.5 mm (single spacers), because the luggage compartment floor then compares at exactly the right height opposite the track height.
The self-supporting frame has now been given bevels at both ends.

In front of it is a copy of the N.V.B.S. working drawing, from which the 1801 will be constructed.
With a length of 16m, this was the longest motor vehicle at the R.T.M. ever.

To create a sturdier frame, long profiles have been attached to the bottom.
These 15mm x 15mm corner profiles are mounted to the frame plate with M3 bolts and easily carry the ballast weight of over 600gr.
This ballast weight of 165x100x12mm will be cut in two equal halves mounted close to the bogies, which will improve the traction and driving characteristics.

The subframe plates on which the non-powered truck and motor truck hang have also been remounted to the frame to obtain the correct floor height compared to B.S. (top of the rail).
After hanging the ballast weights underneath, the first inner walls can be placed.

Once again the reinforced frame with corner profiles and the ballast weight in the middle, here in one piece.
The wagon floor is exactly to scale height with B.S., the subframes are concealed and the spacers have been replaced by pieces of floor part.