ČSD series T 478.3

ČSD series T 478.3 ČD / ZSSK series 750, 753

Numbering:	T 478.3001-3408
Number:	408
Manufacturer:	ČKD / Praha
Year of construction (s):	1970-1977
Axis formula :	Bo'Bo '
Gauge :	1435 mm ( standard gauge )
Length over buffers:	16,540 mm
Height:	4,335 mm
Width:	3,074 mm
Trunnion Distance:	9,000 mm
Bogie axle base:	2,400 mm
Smallest bef. Radius:	100 m
Service mass:	73 t
Wheel set mass :	18.3 t
Top speed:	100 km / h
Installed capacity:	1325 kW
Starting tractive effort:	215 kN
Driving wheel diameter:	1,000 mm
Motor type:	ČKD K 12 V 230 DR
Power transmission:	electric
Tank capacity:	2,500 l
Number of traction motors:	4th
Brake:	DAKO
Train heating:	PG 500 steam boiler

The ČSD series T 478.3 (from 1988 series 753 ) is a diesel-electric universal locomotive of the former Czechoslovak State Railways (ČSD). The locomotives owe their nicknames diving goggles or spectacle snake (Brejlovec) to the striking exterior with the glare-free driver's cabs.

history

The prototype of the series was created in 1968 at ČKD in Prague . Building on the design of the predecessor type T 478.1 , the locomotive was supposed to replace the steam locomotive series 498.0 , 477.0 and 475.1 .

From 1970 onwards, 408 series locomotives were built, which soon shaped traffic on the non-electrified main routes. From 1991 onwards, 163 locomotives were reconstructed, and the outdated steam heating system was replaced by an electric train heater with 3000 V direct current.

With the introduction of the EDP numbering system in 1988, the locomotives were given the new class number 753 with just a 3-digit serial number. The locomotives that were modernized from 1991 onwards were classified as the 750 series.

After the division of Czechoslovakia into the Czech Republic and Slovakia on January 1, 1993, 117 locomotives remained with České dráhy (ČD) and 46 locomotives with Železnice Slovenskej republiky (ŽSR) (today: ZSSK).

The non-modernized locomotives will be decommissioned, at the ZSSK completely by 2008, while the modernized machines are still in use.

Modernizations

753 717 from Unipetrol Doprava

753 607 Unipetrol Doprava in the train station Děčín hln

In 2001, 57 locomotives of the 753 series were sold by ČD to Inekon Holding in Prague. This modernized the locomotives and sold them to Italian railways. Nine locomotives received a used low-speed ČKD six-cylinder engine from the 771 series, and eight of them were sold to Ferrovia Adriatico Sangritana , they were given the series designation D 752.5. The ninth went to SFM Cargo .

31 locomotives received a new Caterpillar engine and Siemens electrics. They were designated as the 753.7 series. They went to various railway companies, including 4 locomotives to Hupac and 18 locomotives to Ferrovie Nord Milano . The train heating system was expanded on both types. Because of the lower UIC vehicle gauge , the roof was flattened and a strip of the side wall was removed. The locomotives also received new fan grilles and, instead of some side windows, additional ventilation openings. The front windows were given bulletproof glass, the driver's cabs were upgraded with air conditioning.

Similarly, 20 locomotives for the Czech private railways OKD Doprava and Unipetrol Doprava were rebuilt , even with a modified body. Other locomotives were rebuilt without any changes to the vehicle gauge.

In 2005 two of these fundamentally modernized locomotives went to ČD. They were given the new series designation 755 . From 2008 to 2010 there were 30 more locomotives than 753.751ff. rebuilt.

In Slovakia, 10 locomotives were modernized to the 756 series between 2008 and 2010. From 2011 to 2015, 25 locomotives were modernized to the 757 series for passenger transport.

The T 478.3001 is looked after as an operational museum locomotive in the Česká Lípa depo, the T 478.3101 as an operational museum locomotive in the ČD Museum Lužná u Rakovníka .

Constructive features

Vehicle body

The locomotives have a bridge frame on which the frame for the side walls is built from sloping profile struts. The box has beaded side walls, only the two prototypes had straight side walls. There are six round windows in the side walls. The bogies were built in an H-shape and are completely welded. The guide for the pivot is located in the middle cross member. The bearings are designed to be laterally displaceable. The pin is supported in the longitudinal axis of the traction vehicle on rubber-metal inserts. Rubber-to-metal stops limit the lateral displacement of the bogies.

The axle bearing guide consists of swing arms. They are connected to the bogie frame via pins inserted in rubber-metal bushings. The suspension of the axes, which are all supported by pivot bearings in swing arms, takes place individually vertically. A pair of cylindrical coil springs and hydraulic dampers are used.

The roof is divided into three segments and can be completely removed for assembly and disassembly work. The main and auxiliary air tanks are located under the front part of the roof, while the cooling system and fan are located in the rear part. The intake ducts of the exhaust silencer are located in the middle part of the roof.

Machine system

The locomotives are powered by a water-cooled four-stroke twelve-cylinder engine ČKD K 12 V 230 DR. In contrast to the engine of the previous series , it is a fast runner. It develops 1,800 hp (1320 kW) at 1,100 rpm and weighs 11,355 kg. The fuel is injected directly. The engine has two exhaust gas turbochargers with charge air cooling. The turbo blower suction line runs through air filters on both sides of the locomotive roof. The exhaust gas energy from the turbocharger takes the shortest route to the turbocharger and, after passing through the turbine parts, is released into the open via the exhaust silencer. The exhaust gas turbocharger's compressor delivers the charge air via an intercooler into the charge lines on the outside of the engine.

A mechanical transmitter with a hydraulic multiplier takes care of the power control. The speed levels are set using an electromotive speed controller. A mechanical safety regulator connected to the camshaft extension protects against exceeding the critical speed of the engine.

The generator is flanged to the rear end of the six-cranked crankshaft. The diesel engine / main generator unit is mounted directly on the main frame in the middle part of the engine room. The main generator is a ten-pole direct current machine with external excitation of the type TD 802 E-ČKD . A belt pulley is arranged on the extended generator shaft, which drives the fan for cooling the traction motors of the front bogie via V-belts. In addition, the exciter and the hydrostatic drive of the compressor are driven by V-belts. There is a second pulley at the other end of the crankshaft. From here the fans for the traction motors of the rear bogie are driven via V-belts. The pumps for the hydrostatic drive of the cooling fans are also driven from there.

The drive motors are four-pole pivot bearing motors of type TE 005 C-ČKD , which are elastically mounted in the bogie.

The roof of the first locomotives including the ribbon windows was dark green, the lower vehicle body was dove gray and the frame dark gray. From the T 478.3128 onwards, the locomotives were painted entirely in cherry red.

Cooling system

The cooling system is divided into two systems; on the one hand the cooling of the diesel engine cooling water and on the other hand the cooling of the oil and the charge air of the turbocharger . Both circuits have a common expansion tank. In total, the two circuits are cooled by four fans. These with a diameter of 630 mm are located in the rear part of the machine room. Thermostats regulate the activation of the fans. The fans have hydrostatic drive motors. At the same time, the side blinds are connected to the cooling elements.

Auxiliary equipment

The locomotive has a type 3 DSK 100 compressor to supply the compressed air for the air brake . It has a nominal output of 120 m ³ / h and a nominal outlet pressure of 10 bar. It is also hydrostatically driven and therefore delivers a constant amount of air regardless of the engine speed.

The compressed air brake of the DAKO system is controlled with the driver's brake valve BS 2 . The BP valve is used for the direct-acting brake .

The locomotive originally had an oil-fired steam heating system of the type PG 500 . It had an output of approx. 580 kW. It was housed in the front part of the locomotive. The water tanks with a capacity of 3,000 l were located between the bogies under the main frame. In the 1990s this outdated heating was replaced by an electric heater.