Traction electric motor ЭДП810 electric locomotive 2ES6

Appointment

Electric motor ЭДП810 direct current independent excitation is installed on bogies of the 2ES6 electric locomotive and is intended for traction drive of wheelsets.

Technical characteristics of the electric motor ЭДП810

The main parameters for hourly, continuous and limiting operating modes of the traction motor are shown in Table 1.1.

The main parameters of the electric motor ЭДП810

Parameter name	unit of measurement	Working hours
		hourly	continue corporeal
Shaft power	kw
Power in braking mode, no more: With recuperation With rheostat braking	kw	1000
Rated voltage at the terminals		1500
Maximum terminal voltage		4000
Armature current
Armature current when starting off, no more
Rotation frequency	s-1 rpm	12.5	12.83
Highest speed (achieved with an excitation current of 145 A and an armature current of 410 A)	s-1 rpm	1800
Efficiency		93,1	93,3
Shaft torque	Nm kgm	10300 1050	9355
Starting torque, no more	Nm	17115
Cooling		Air forced
Cooling air consumption	m3 / s	1,25
Static air pressure at the test point	Pa	1400
Excitation of the electric motor		Independent
Field winding current
Excitation current when starting off, no more
Nominal operating mode		hourly according to GOST 2582
Resistance of windings at 20оС: Anchors Main poles Additional poles and compensation winding	Ohm	0.0368 ± 0.00368 0.0171 ± 0.00171 0.0325 ± 0.00325
Heat resistance class of armature winding insulation, main and auxiliary poles
Mass of the electric motor, no more	Kg	5000
Anchor weight, no more	Kg	2500
Stator mass, no more	Kg	2500

The main parameters of cooling the electric motor ЭДП810

Parameter name	Meaning
Air consumption through traction electric motor, m3 / s	1,25
Air consumption in interpole channels, m3 / s	0,77
Air flow through the armature channels, m3 / s	0,48
Flow velocity in interpole channels, m / s	26,5
Flow velocity in the armature channels, m / s	20,0
Air pressure at the inlet before the engine, Pa (kg / cm2) (mm.water column)	1760 (0,01795) (179,5)
Pressure at the control point (in the hole in the cover of the lower manifold hatch), Pa (kg / cm2) (mm.water column)	1400 (0,01428) (142,8)

The design of the electric motor ЭДП810

The electric motor is a compensated six-pole reversible direct current electric machine of independent excitation and is designed to drive wheel pairs of electric locomotives. The electric motor is designed for axial support and has two free tapered shaft ends for transmitting torque to the axle of the wheelset of the electric locomotive through a gear train with gear ratio 3,4.

External views of the armature and the body of the ЭДП810 electric motor are shown in Figures 14 and 15, the design of the electric motor is shown in Fig.16.

Figure 14 - Anchor of the electric motor ЭДП810

Figure 15 - Electric motor housing ЭДП810

Figure 16 - The design of the electric motor ЭДП810

The motor housing is round, welded construction, made of mild steel. On one side of the housing, there are seating surfaces for the housing of motor-axial bearings, on the opposite side - a mating surface for fixing the electric motor on the bogie of the electric locomotive. The housing has two necks for installing end shields, an inner cylindrical surface for installing the main and additional poles, a ventilation hatch is made on the side of the collector for supplying cooling air to the electric motor and two inspection hatches (upper and lower) for servicing the collector. The body is also a magnetic circuit.

The armature of the electric motor consists of a core, thrust washers and a manifold pressed onto the armature body, into which the shaft is pressed.

The shaft is made of alloy steel with two free tapered ends for seating gears of gear reducers, at the ends of which there are holes for oil scraper of the gear. In operation, due to the presence of the housing, if repair is necessary, the shaft can be replaced with a new one.

The armature core is made of 2212 grade electrical steel sheets, thickness 0.5 mm , with an electrically insulating coating, has grooves for winding laying and axial ventilation ducts.

Armature winding - two-layer, loop, with equalizing connections. The armature winding coils are made of rectangular copper winding wire of the PNTSD brand, insulated with a "NOMEX" tape, protected by glass threads. The winding insulation is made with Elmikaterm-529029 tape, which is a composition of mica paper, electrical insulating fabric and polyamide film impregnated with Elplast-180ID compound. Vacuum - injection impregnation of the armature in "Elplast-180ID" compound provides heat resistance class "H" in the composition with body insulation.

The collector is made up of cadmium-doped copper collector plates, tightened into a set using a cone and a sleeve with collector bolts.

Brush-collector unit parameters

Parameter name	Dimensions in millimeters
Collector diameter
Manifold working length
Number of collector plates
Collector micanite thickness
Number of brackets
Number of brush holders in brackets
Number of brushes in the brush holder
Brush brand	EG61A
Brush size	(2x10) x40

The cores of the main poles are laminated and are attached to the body with through bolts and rods. Independent excitation coils made of rectangular wire are installed on the cores. Vacuum - injection impregnation in the "Elplast -180ID" type compound provides the "H" class of heat resistance in the composition with body insulation based on mica tapes.

The cores of the additional poles are made of strip steel and are attached to the frame with lead-through bolts. On the cores there are coils wound from busbar copper on an edge. Coils with cores are made in the form of a monoblock with vacuum-injection impregnation in a compound of the "Elplast-180ID" type, which provides a heat resistance class in a composition with case insulation based on mica tapes. -529029 ", and installed in the grooves of the cores of the main poles, the heat resistance class of the coils" H ".

Two end shields with roller bearings of the NO-42330 type are pressed into the housing. Bearing grease is consistent type "Buksol". In the end shield on the side opposite to the collector there are openings for cooling air out of the armature.

On the inner surface of the end shield from the side of the collector, a traverse with six brush holders is fixed, which allows rotation by 360 degrees and provides inspection and maintenance of each brush holder through the lower housing hatch.

On top of the electric motor, on the body, there are two detachable terminal boxes, which serve to connect the power wires of the electric locomotive circuit and the output wires of the armature winding circuit and the excitation winding circuit of the electric motor. The diagram of the electrical connections of the windings is shown in Figure 1.9.

Figure 17 - Diagram of electrical connections of the windings of the electric motor ЭДП810

Operating instructions

Checklist technical condition

What is checked	Technical requirements
1 External state of the motor	1.1 No damage or contamination, and no traces of grease leakage from the bearings
2 Insulation of windings.	2.1 Absence of cracks, delamination, charring, mechanical damage and contamination. 2.2 The value of the insulation resistance should be: At least 40 megohms in a practically cold state before installing a new electric motor on an electric locomotive; Not less than 1.5 MOhm in a practically cold state and before the electric locomotive is put into operation after a long stay (1-15 days or more).
3 Brush holders	3.1 Absence of melting, disturbing the free movement of brushes in the cages or capable of damaging the collector. 3.2 No damage to the housing and springs.
4 The gap between the brush holder and the working surface of the collector is measured with an insulating plate (for example, made of textolite, getinax) of appropriate thickness.	4.1 The gap between the brush holder and the collector should be 2 - 4 mm (with a compressed crosshead, the measurement carry out only on the lower brush holder). 4.2 No loosening of the fastening of the brush holders to the strips, the tightening torque of the bolts is 140 ± 20 Nm (14 ± 2 kgm). The fastening bolts must be secured against self-loosening.
5 Brushes	5.1 Free movement of brushes in the holder of the brush holders 5.2 Absence of traces of damage to current-carrying wires. 5.3 Absence of cracks and edge chips at the contact surface more than 10% of the cross-section. 5.4 Absence of one-sided working of edges. The contact surface of the brush running-in to the collector must be at least 75% of its cross-sectional area. 5.5 The bolts of fastening the current-carrying wires of the brushes to the body of the brush holder must be secured against self-loosening. 5.6 Brush pressure should be 31.4 - 35.4 N (3.2 - 3.6 kg).
6 Traverse	6.1 No loosening of the traverse (pin tightening torque 250 ± 50 Nm (25 ± 5 kgm)). 6.2 Lack of contamination and damage. 6.3 The alignment of control marks on the traverse and the body should be with a permissible deviation of no more than 2 mm.
7 Collector working surface.	7.1 Smooth, from light to dark brown color, without scoring, without traces of melting from electric arc surges, without burns that cannot be removed by wiping, without coating of copper and dirt. 7.2 Development under the brushes should be no more than 0.5 mm ; groove depth 0.7 - 1.3 mm. 7.3 Contact with the collector of fuels and lubricants, moisture and foreign objects is not allowed.
8 Static pressure of cooling air	The static pressure in the opening of the lower manhole cover should be 1400 Pa ( 143 mm water column).

More detailed instructions on the operation of the electric motor ЭДП810У1 are set out in the operating manual КМБШ.652451.001РЭ.

"RUSSIAN RAILWAYS"

BRANCH OF OPEN JOINT STOCK COMPANY

SVERDLOVSK RAILWAY

Yekaterinburg Training Center No. 1

ELECTROVOZ 2ES6

Mechanics, engines, apparatus

EKATERINBURG

The manual was compiled on the basis of materials proposed by the manufacturer of the UZZhM for the operation of 2ES6 electric locomotives on the Sverdlovsk railway branch of Russian Railways. The manual provides the manufacturer's recommendations for troubleshooting.

The proposed material is a teaching aid for locomotive crews and students of training centers for the training of drivers, assistants to electric locomotive drivers and repair personnel.

1 General

The mechanical part is designed for the implementation of traction and braking efforts developed by the electric locomotive, the placement of electrical and pneumatic equipment, ensuring a given level of comfort, convenient and safe conditions for controlling the electric locomotive.

The mechanical (carriage) part of the electric locomotive consists of two sections interconnected by an automatic coupler. Each section includes two biaxial bogies and a body, interconnected by inclined rods, spring spring suspension of the "fleiscoil" type, hydraulic dampers and body movement limiters.

The mechanical part of the electric locomotive is subject to the load created by the weight of the mechanical, electrical and pneumatic equipment. In addition, the mechanical part transmits traction forces from the electric locomotive to the train and perceives the dynamic loads arising from the movement of the electric locomotive along curved and straight sections of the track. The mechanical part must be strong enough and also meet traffic safety requirements and regulations technical operation railways. To ensure normal and trouble-free operation, it is essential that all mechanical equipment was in full working order and met safety standards, strength and repair rules.

The mechanical (carriage) part of one section of the 2ES6 electric locomotive is shown in Figure 1.

Figure 1 - Mechanical (carriage) part of one section.

2 Trolley

Each section includes two biaxial bogies on which the body rests. The bogies perceive traction and braking forces, lateral, horizontal and vertical forces when passing uneven paths and transmit them, through spring supports with lateral flexibility, to the body frame. The bogie of the 2ES6 electric locomotive has the following technical characteristics (Figure 2):

Design speed, km / h 120

Load from a wheel pair on rails, kN 245

Type of traction electric motor ЭДП810

Type of engine mounting support-axial

The engine mount is support-axial with a pendulum suspension

Type of axleboxes single-shaft with cassette roller bearing

Spring suspension two-stage

Static deflection, mm

axle step 58

body stage 105

Type of brake cylinders TCR 8

Coefficient of pressing brake pads 0,6

The bogie consists of a welded box-section frame, which by its end beam is connected to the central part of the body frame through an inclined link with hinges. The bogies are attached to the middle beam of the frame by means of pendulum suspensions of the frame of DC traction motors, which with their other sides rest on the axles of the wheel pairs through motor-axial rolling bearings mounted on them. The torque from the traction motors is transmitted to each axle of the wheelset through a two-way helical gear, forming a chevron engagement with gears mounted on the shanks of the traction motor armature shaft.

On the axle journals of the axle of the wheelset, double-row tapered roller bearings of the closed type of the Timken company are mounted, placed inside the body of the jawless single-drive axle box. The levers have spherical rubber-metal hinges, which are attached to the axle box and to the bracket on the sidewalls of the bogie frame by means of wedge grooves, forming a longitudinal connection of the wheelsets with the bogie frame.

The transverse connection of the wheelsets with the bogie frame is carried out due to the transverse flexibility of the axle springs. Likewise, the lateral connection of the body with the bogie frame is carried out due to the lateral flexibility of the body springs and the stiffness of the stop-stop springs, which also provide the ability to rotate the bogie in curved sections of the track and damp various modes of vibration of the body on the bogies. Also, to damp vibrations of the body and the sprung parts of the bogie, vertical axle boxes, vertical and horizontal body hydraulic dampers (hydraulic vibration dampers) are used.

To decelerate the electric locomotive, a brake linkage is used with the use of cast-iron brake pads, eight-inch brake cylinders (for each wheel of the bogie) with an automatic stem exit regulator.

A.A. Malgin

ELECTROVOZ 2ES6

Mechanics, engines, apparatus
(manual for locomotive crews)

EKATERINBURG

2010

The manual was compiled on the basis of the operation manual and other materials offered by the manufacturer of the UZZhM for the operation of 2ES6 electric locomotives on the Sverdlovsk Railway, a branch of Russian Railways. The manual contains technical data and design of mechanical parts, electrical devices and electric motors.

The proposed material is a methodological guide for training locomotive crews, repair personnel and students of training centers for the training of drivers and assistants to train drivers of an electric locomotive.

Mechanical part of an electric locomotive 2ES6

The mechanical part is designed to realize the traction and braking forces developed by the electric locomotive, to accommodate electrical and pneumatic equipment, to ensure a given level of comfort, convenient and safe conditions for controlling the electric locomotive.

The mechanical (carriage) part of the electric locomotive consists of two sections interconnected by an automatic coupler. Each section includes two biaxial bogies and a body, interconnected by inclined rods, spring spring suspension of the "fleisoil" type, hydraulic dampers and body movement limiters.

The mechanical part of the electric locomotive is subject to the load created by the weight of the mechanical, electrical and pneumatic equipment. In addition, the mechanical part transmits traction forces from the electric locomotive to the train and perceives the dynamic loads arising from the movement of the electric locomotive along curved and straight sections of the track. The mechanical part must be strong enough, and also meet the requirements of traffic safety and the rules of technical operation of railways. To ensure normal and trouble-free operation, it is necessary that all mechanical equipment is in full working order and meets safety, strength and repair rules.

The mechanical (carriage) part of one section of the 2ES6 electric locomotive is shown in Figure 1.

Figure 1 - Mechanical (carriage) part of one section.

1 - automatic coupler;

2 - a cabin;

3 - wheelset;

4 - axle box;

5 - box leash;

6 - trolley frame;

7 - partition;

8 - bracket;

9 - inclined draft;

10 - body roof;

11 - shock absorber;

12 - body frame;

13 - box spring;

14 - body spring;

15 - safety pin;

16 - bracket;

17 - side wall;

18 - back wall;

Transition area.

Cart

characteristics (figure 2):

Figure 2 Trolley

Design speed, km / h 120

Load from the wheel pair on the rails, kN 245

Type of traction electric motor ЭДП810

Type of engine mounting support-axial

The engine mount is support-axial with a pendulum suspension

Type of axleboxes single-shaft with cassette roller bearing

Spring suspension two-stage

Static deflection, mm

axle step 58

body stage 105

Type of brake cylinders ТЦР 8

Coefficient of pressing brake pads 0,6

2ES6 "Sinara"

Photo

Manufacturing plants

JSC "Ural Plant of Railway Engineering" (UZZHM)

Years of construction: 2006-2010
Built sections: XXX
Machines built: XXX

LLC Uralskie locomotives (joint venture of CJSC Sinara Group and Siemens AG concern)

Plant location: Russia, Sverdlovsk region, Verkhnyaya Pyshma
Years of construction: 2010-
Built sections: XXX
Machines built: XXX

Sections built for the entire period: 794 (up to 06.2014)
Cars built for the entire period: 397 (to 06.2014)

Technical details

PS type: electric locomotive
Service: mainline cargo
Track width: 1520 mm
KS current type: constant
KS voltage: 3 kV
Number of sections: 2
Locomotive length: 34 m
Coupling weight: 200 t
Design speed: 120 km / h
Hour mode speed: 49.2 km / h
Continuous mode speed: 51 km / h
Number of axles: 8
Axial formula: 2 (2o-2o)
Wheel diameter: 1250 mm
Load from moving axles on rails: 25 tf
Traction motor type: collector
Hourly power of TED: 6440 kW
Continuous power of TED: 6000 kW
Hourly traction force: 47.3 tf
Continuous traction: 42.6 tf

Total information

Countries of systemic operation: Russia
Systemic roads: Sverdlovsk, West Siberian (since 2012)
Systemic operation areas: Yekaterinburg-Sortirovochny - Voinovka, Voinovka - Omsk - Novosibirsk (since 2010), Yekaterinburg-Sortirovochny - Kamensk-Uralsky - Kurgan - Omsk (since 2010), Kamensk-Uralsky - Chelyabinsk - Kartaly (since 2010) G.)

Explanation of the abbreviation: "2" - two-section, "E" - electric locomotive, "C" - sectionalized, "6" - model number, "Sinara" - a river in the east of the Sverdlovsk region, a plant in Kamensk-Uralsky (OJSC "Sinarsky pipe plant")
Nicknames: "Cigar", "Swinara"

Description

The body of the electric locomotive is all-metal, has a flat skin surface. The design of the cabin has something in common with the Kolomna diesel locomotives. Suspension of traction motors - typical for freight electric locomotives - axial support, but with progressive motor-axial rolling bearings. The axles are jawless. Horizontal forces are transmitted from each axle box to the bogie frame by one long rubber-metal leash.

At 2ES6, the following are used: rheostat start of traction electric motors, rheostat braking with a power of 6600 kW and regenerative braking with a power of 5500 kW, independent excitation from semiconductor converters in braking and traction modes.

Independent excitation in traction is the main advantage of Sinara over the VL10 and VL11 electric locomotives: it increases the anti-slip properties and efficiency of the machine, and allows for a wider power control. Also, independent excitation plays an important role in rheostatic starting: with increased excitation, the opposite electromotive force motors and the current drops faster, which allows you to bring the rheostat at a lower speed, saving energy. With jumps in the armature current at the moment of switching on the contactors, the microprocessor control and diagnostic system (MCS & D) abruptly supplies additional excitation, reducing the armature current and thereby leveling the jump in the thrust at the moment of recruiting the next position (it should be noted, often leading to slipping on electric locomotives with step regulation) ...

Electric locomotive engine with successive arousal has a tendency to skidding at different speeds: with an increase in the rotational speed, the armature current falls, and with it the excitation current - thus, self-relaxation of the excitation occurs, leading to a further increase in frequency. With independent excitation, the magnetic flux is preserved, and with an increase in frequency, the opposite electromotive force sharply increases and the thrust force decreases, which does not allow the engine to go into drift slip. The 2ES6 microprocessor control and diagnostic system, when slipping, supplies the engine with additional excitation and starts the mechanism for feeding sand under the wheelset, minimizing slipping.

However, in addition to the obvious advantages of "Sinara", some disadvantages were also discovered. The design of traction motors leads to periodic flashes of the electric arc along the collector, burnouts of cones, breakdowns of anchors. In addition to TED failures, malfunctions of such units as PC electropneumatic contactors, BK-78T high-speed contactors, auxiliary machines (compressor units and TED blowers) were noted.

History

A prototype 2ES6 electric locomotive was produced in November 2006.

On December 1, 2006, the electric locomotive was presented to the leadership of the United Russia party, which is why 2ES6-001 received a patriotic paint scheme and corresponding inscriptions on the sides.

After commissioning tests carried out in May and June 2007 at EERZ, the electric locomotive was sent for certification tests of an initial batch to the test ring of VNIIZhT in Shcherbinka.

At the end of July 2007, a contract was signed between Russian Railways and UZZhM for the supply of 8 electric locomotives in 2008 and 16 in 2009.

By December 2007, the 2ES6-001 electric locomotive had a mileage of 5000 km.

In parallel, in 2007, an electric locomotive 2ES6-002 was undergoing trial operation on the Yekaterinburg-Sortirovochny - Voinovka section of the Sverdlovsk railway. In early September, he took part in the Magistral-2007 exhibition at the Prospector training ground, and by December he already had a mileage of 3400 km.

By the beginning of 2008, traction-energy and braking tests, as well as tests on the impact on railroad track electric locomotive 2ES6-001.

In February and March 2008, the 2ES6-002 electric locomotive passed certification tests on the VNIIZhT test ring

On October 15, 2008, it was officially announced that the first stage of the production complex for the serial production of 2ES6 electric locomotives was launched.

At the beginning of September 2009, 2ES6-017 took part in the Magistral-2009 exhibition at the Staratel test site, and 2ES6-015 at the EXPO-1520 exhibition at the VNIIZhT EC, after which it remained for the next certification tests - for serial production.

In early September 2011, 2ES6-126 took part in the EXPO-1520 exhibition at the VNIIZhT EC.

In mid-September 2011, on the Kedrovka - Monetnaya stretch, tests were carried out for compliance with safety standards when changing the auxiliary converter (PSN) of the 2ES6-119 electric locomotive. A month later, the same tests with the same machine were carried out at EK VNIIZhT.

In February 2012, an electric locomotive 2ES6-147 was sent to Ukraine (depot Lviv-West) to undergo two-month test tests.

On April 16, 2012, the Interdepartmental Commission signed an act allowing the operation of 2ES6 and 2ES10 electric locomotives in Ukraine. An agreement was signed on the supply of electric locomotives, which will come into effect after the provision of loans to Ukraine.

BRANCH JSC "Russian Railways"

WESTERN SIBERIAN RAILWAY

OMSK TECHNICAL SCHOOL

ELECTRIC CARGO

2ES6 "SINARA"

Mechanical equipment of the 2ES6 electric freight locomotive.

The mechanical part is designed to implement the traction and braking forces developed by the electric locomotive, to place electrical and pneumatic equipment, to ensure a given level of comfort, convenient and safe working conditions for locomotive crews.

The mechanical part of the electric locomotive is subject to the load created by the weight of the mechanical, electrical and pneumatic equipment. In addition, the mechanical part transmits traction forces from the electric locomotive to the train and perceives the dynamic loads arising from the movement of the electric locomotive along curved and straight sections of the track. The mechanical part must be strong enough, and also meet the requirements of traffic safety and the rules of technical operation of railways. To ensure normal and trouble-free operation, it is necessary that all mechanical equipment is in full working order and meets safety, strength and repair rules (see Fig. 1).

Fig. 1. - Mechanical (carriage) part of one section.

1 - automatic coupler; 2 - a cabin; 3 - wheelset; 4 - axle box; 5 - box leash; 6 - trolley frame; 7 - partition; 8 - bracket; 9 - inclined draft; 10 - body roof; 11 - shock absorber; 12 - body frame; 13 - box spring; 14 - body spring; 15 - safety pin; 16 - bracket; 17 - side wall; 18 - back wall; 19 - transition platform

Body

The body of the section of the electric locomotive is single-cabin, wagon-type, designed to accommodate power and auxiliary electrical equipment, pneumatic equipment of a locomotive, ventilation systems, placement of workplaces of a locomotive crew, as well as for receiving and transferring loads:

The forces of gravity from the mass of the in-body equipment and the supply of sand;

Gravity from the mass of the roof and underbody equipment;

Static and dynamic, arising from interaction with train wagons and locomotive bogies in the mode of traction, coasting and braking, and shock effects into the coupler. The body is an all-metal welded structure with a supporting frame (see Figure 2).

1 - spotlight; 2 - installation of air conditioning; 3 - antenna CLUB; 4 - GPS antenna; 5 - pantograph; 6 - interference suppression choke; 7 - disconnector; 8 - radio station antenna; 9 - current-carrying bus; 10 - block of starting and braking resistors; 11 - auxiliary compressor; 12 - compressor unit; 13 - TETRA antenna; 14 - transition platform; 15 - detachable sheet; 16 - down-conductor device; 17 - traction motor; 18 - block battery; 19 - inclined draft; 20 - block of electrical equipment VVK; 21 - DPS-U sensor; 22 - typhon, whistle; 23 - SAUT antenna, ALSN receiving coils; 24 - broomstick.

The body of the electric locomotive consists of two sections, identical in the main units, with the exception of the place where the bathroom is installed, it is installed only on the first section. The locomotive body consists of a body frame, a body roof and an outer skin made of smooth steel sheet 2.5 mm thick. and sand bunkers. At the first end of each section, space is left for the installation of a modular cabin. Inside the body, a room is formed for installing equipment - an engine room, fenced off by a transverse wall forming a vestibule from the control cabin. In the vestibule there are doors to enter the locomotive and passages to the cab and engine room.

On the end walls of the body there is a place for the installation of the main tanks.

Shock and traction devices are installed on the body frame of the electric locomotive.

The body of the section of the electric locomotive is divided into sections in the vertical and horizontal plane:

The roof of an electric locomotive is shown in Fig. 3 and consists of a main part (935 mm high and 3060 mm wide) and three removable parts. ... The rear part is made in one piece with the body frame. Removable sections are a frame made of rolled and bent sections sheathed with sheet steel. The middle removable roof consists of two sections, each section containing a brake resistor cooling module. The joints of the removable parts with the body frame are sealed to prevent moisture from entering the body. At the rear of the section there is a hatch with a cover for exiting the body to the roof.