Reconstructing trams at our main workshops
The attractive, modern appearance of Vario trams undoubtedly makes them a popular feature of local public transport in Brno. They can be seen on the streets in the form of the single-carriage Vario LFR.E, created with the reconstruction of the T3 model, and the articulated Vario LF2R.E, which was originally the K2 model. These new trams are built in cooperation with Aliance TW Team, a consortium of companies, with the main workshops operated by Brno Public Transport Authority (DPMB) playing a considerable part in their creation. First of all, however, the depot must strip the original tram to be able to use some of its parts. The registration number remains too, which somewhat complicates the task of finding your way around the history of the fleet given that the number is used more than once.
The life of a new Vario tram begins in Silesia. The repair and engineering works in Krnov make the entire frame of the vehicle. Once our employees take charge of the frame, it is transferred to Brno, to our main workshops, by trailer.
In the meantime, around a month and a half in advance, however, our assembly workers prepare the cabling for the future tram. The frame which is delivered is checked at the body shop and if everything is as it should be, the carpenters can get to work. The first task is to prepare a floor for the frame. We will come back to this later. The tram is then transferred to the paint shop, in two pieces if it is articulated. Painting consists of several stages. Head of the paint shop Miroslav Šimiček describes the whole process: The first stop is the degreasing cabin, followed by the jointing shop, where the frame spends 3 days. The outer and inner sides of the surface must be “harmonised”, any protrusions left after welding removed and sanded. Only then can the vehicle move to the spraying cabin. On the first day, the interior is painted white and grey and then covered in paper so that the areas already done are not spoiled. The vehicle does not have any windows at this point. The outside – the curves of the roof and the belt beneath the windows - is painted on day two and on day three the area around the windows. Everything is again covered in paper. Then comes the red paint, the main belt on the side of the tram. The masking paper is removed on day four, the central area of the roof is finished and final adjustments are made. The tram is then passed on to the electricians.
In the meantime, the other components required are gathered from individual suppliers. The traction gear, the seats (we have our own upholstery for these) and components for the undercarriage, not including transmission, because again we do this ourselves. There is, of course, an inordinate amount of other, smaller pieces of material involved.
The next stage in tram reconstruction is the cabling.Heavy maintenance electrics foreman Vladimír Vahalík briefly describes the whole complicated process: Cabling requires thorough preparation long before the frame arrives. Cables are marked with numbers and it is determined where they will go. Bundles are made and these run from points such as the driver’s cabin to other aggregates. There are around 12-13 kilometres of 24 V weak current conductors in an articulated Vario. This part is prepared by the female members of the team, the heavy 600 V power or traction cables remaining for the men. There are around 400 metres of these in the tram. Everything that can be prepared in advance is done in the workshop, outside the tram itself. The vehicle is painted while the cables are being readied and the electricians can then get to work. Mechanics install the cable bundles in the specified places. The batteries are then installed, meaning all the equipment required for electric drive (beginning with the control panel in the driver’s cabin and continuing with the door controls, equipment for the Control and Information System, the camera system, lighting, heating etc.). The traction gear is supplied by companies such as Pragoimex and Cegelec. Cables are then connected to the aggregates through tubes and other prepared routes. Mechanics have special tools and devices for all this work, to make it all that bit simpler. The work is so specific that any change, for example a change in the component supplier, causes major problems and a delay in the time schedule. Cables must obviously comply with the relevant standards and regulations, especially special Radox 600 V traction conductors. It takes up to 4 days to install the cables in one articulated carriage (in addition to prior preparation), in that both carriages are done at the same time. Ten workers take part in installation at this stage of reconstruction.
While work is ongoing on installing cables in the tram, other workers at our main workshops prepare other parts of the future Vario. Heavy maintenance foreman Jaroslav Kozel provides an introduction: For example, windows are installed and sealed in, the driver’s cabin is prepared and, fixtures for electrical gear and terminal boxes, around one month before the electricians move in. There is also the work of the carpenters, preparing the floor of the tram. This is made of plywood of 18 mm in thickness. Individual parts are cut and fitted together, then removed again. Painters get to work and, before the boards dry, rubber elements to counteract vibration are glued to the frame of the tram. The plywood is then placed on the rubber and screwed in tight. The floor is sanded and the tram goes to the paint shop, adds Jan Krištof, head of the carpentry and upholstery shop.
The ceiling, the base of which is brought in from the repair and engineering works in Krnov, is then fixed to the vehicle. Rubber blocks are fixed at 15 cm intervals, the shops apply a special coat of paint, glue is applied and the ceiling is glued in.
The ceiling is lined with special ABET lining in the curves between ceiling and wall where passengers see advertisements. J. Kozel goes on: The windows are then fitted, while electricians install the switchboard in the meantime. We put together the driver’s cabin, we complete the sand blaster, the doors and door drive systems are installed and fixtures for roof boxes to hold the electric gear are fitted. The ceilings are completed after installing ceiling cables, the Altro anti-slip floor covering is applied and panelling is placed around the windows – more gluing – before the seats and handles are fitted. The roof of the vehicle is then provided with rubber insulation to cover the situation in which the collector falls, for example, or other maintenance needs to be done, adds J. Krištof.
In addition to all other work, we still need to prepare the undercarriage of the vehicle, which is prepared separately to the body. Head of our main workshops Ing. Tomáš Chaloupecký describes this stage of reconstruction: Undercarriages known as KOMFORT differ from the original undercarriages, particularly in terms of the frame, which is made by the repair and engineering works in Krnov, the suspension system and the placing of the vehicle on the undercarriage. The transmission system and the axle and wheels remain of the original. We put together the transmission at the main workshops ourselves and press the wheels for the axle. The undercarriage is driven by two asynchronous motors. One motor has a power of around 90 kW. Installing the undercarriage is not simply about its mechanical part. Cabling must also be fitted to the undercarriage, mechanics now doing this on their own without the help of the electrics section at the main workshops. Power cables must be fitted to drive the motors and weak current cables fitted, let’s say for diagnostics, rail brakes and other activity, such as the load sensor to ensure maximum use of adhesion conditions.
Pivot pins must be fixed on before the body of the tram is fitted to the undercarriage, the body is hoisted and lowered on to the undercarriage. Dividers and couplers are then completed. In articulated Varios, there is also the need to install the moving connecting section of the front and rear parts, meaning the “bellows”, crosswalk and turntable, and to connect both parts of the tram in terms of electrics.
Ing. Chaloupecký tells us of the tram’s onward journey from workshop to track and passengers: After all this work has been done, the vehicle is ready to go to the test shop. It is here that electricians and electronics workers “bring it to life”. This stage proceeds in cooperation with Pragoimex, which supplies the software. After coming alive, the vehicle can then be connected to 600 V voltage for the first time and head out for a test run. It travels around 250 kilometres, after which there follow technical and safety tests. The main focus here is the functioning of the vehicle’s brake system. Records and other documentation are handed over to the Rail Authority, which must make a statement on the fitness of the vehicle to transport passengers within 30 days. In the meantime, the main workshops pass the tram on to technical operations. Naturally, the tram must be carefully cleared and cleaned inside and out. Once the “papers” arrive from the Rail Authority, there is nothing to stop the tram embarking on its first journey with passengers.
All this work is continually interwoven, meaning that it is practically impossible to order it all from a to z, which makes it all somewhat confusing. What is important, though, is that workers at the main DPMB workshops manage it all with oversight and with comparative ease. Articulated trams spend around 80 days at the main workshops and single carriages 62.
Six Vario LFR.E trams (single-carriage) and 3 Vario LF2R.E trams (articulated) were completed and put into service in 2013.
Another 6 single-carriage trams and 6 articulated were then completed and put into operation in 2014.
Another 9 single-carriage trams and 3 articulated were then completed and put into operation in 2016.
Overview of Vario trams as at 1. 1. 2017
A total of 28 Vario LFR.E (single-carriage)
1497, 1523, 1530, 1539, 1541, 1551, 1553 - 1557, 1567, 1573 - 1575, 1580, 1582, 1584, 1586, 1590, 1592, 1596 - 1599, 1601, 1605, 1617
In all cases this is at least the second time the same registration numbers have been used (three times in three cases).
A total of 26 Vario LF2R.E (articulated trams)
1069, 1072, 1078, 1082 - 1084, 1088, 1090, 1092 - 1094, 1096, 1098 - 1103, 1106, 1108, 1109, 1112, 1114, 1117, 1127, 1131
In this case too the same registration numbers are being used for the second time (three times in two cases).