Driver's crane 394 appointment device action. Brief description of the crane driver. Operational locomotive depot

Kulunda Dortech School
- structural subdivision of the Altai branch - structural subdivision of the West Siberian railway
- branch of the open joint stock company "Russian Railways"

Teacher of special disciplines A.V. Goncharov

METHODOLOGICAL DEVELOPMENT
On the topic “Driver's crane conv. 395 "

METHODOLOGICAL DEVELOPMENT
On the topic “Driver's crane conv. 395 "

1. Purpose

The driver's crane is designed for remote control of pneumatic and electro-pneumatic train brakes.
The reliability of the brakes on the train largely depends on the crane driver.

2. Crane properties

Universal with two non-automatic overlaps - with and without power supply of the brake line
- short-term holding of increased pressure in the line when the handle is moved to position II after braking;
- the possibility of recharging the line with the subsequent automatic transition to normal charging pressure;
- maintaining the pressure in the line at position IV; disconnection of the brake line from the feed line at position III;
- holding in position I not according to the countdown, but according to the pressure gauge of the surge tank.

The disadvantages of cranes include:
- the presence of a large spool, which must be lubricated frequently;
- overestimation of pressure in the equalizing tank and brake line with a leaky reducer valve or spool;
- change in pressure in the surge tank on the overlap after service braking (temperature change during braking);
- stressful work of the reducer membrane due to high pressure in the chamber above the membrane, which leads to its damage;
- lack of automaticity when the train breaks due to powerful power supply in the train position.

This power supply is necessary for quick release, recharging the brakes and replenishing leaks in the brake network.

Devices allowing to control a brake line break (sensor No. 418), and in passenger ones - emergency braking accelerators (in air distributors No. 292-001).

Driver's cranes No. 394 and 395 refer to the spool-piston design. In this type, the distribution body is a round brass spool, lapped against a cast-iron mirror, and the equalizing body is a piston sealed by a metal ring lapped to the bushing, in combination with or without a rubber cuff.

Also, the driver's taps are of the valve-diaphragm type in which rubber diaphragms and cuffs and valves with rubber seals serve as sealing and distributing elements and organs.

3. Modifications to the crane operator

The following modifications of the driver's crane are applied. No. 395, which differ in the number of controller microswitches and their switching circuit:
- conv. No. 395-000 with two microswitches - on passenger locomotives;
- conv. No. 395-000-3 with one microswitch for freight locomotives with engine shutdown and sandbox activation in VI position of the crane handle.
- conv. No. 395-000-4 with three microswitches - on passenger locomotives;
- conv. No. 395-000-5 with two microswitches - on electric trains and diesel trains;
- conv. No. 394-000-2 has position VA (at the driver's cranes, service. No. 395-000, 395-000-4 and 395-000-5 is designated as position VЭ), in which the brake valves of the electric air distributors are excited with the discharge of the surge tank through the hole with a diameter of 0.75 mm. With pneumatic control of automatic brakes, the action of the driver's crane conv. No. 395 of all modifications is the same as the crane conv. No. 394-000-2.

4. The device of the crane operator

Driver's crane No. 395 is assembled from five main parts:
- top 1 (spool valve),
- middle 3 (intermediate or spool mirror),
- lower 6 (equalizing),
- reducer 5 (feed valve) and
- stabilizer 4 (throttling exhaust valve).
On the flange 8 of the upper part, the serial number of the crane from the beginning of the year is stamped, as well as the last two digits of the year and the month of manufacture of the crane.

1 nut; 2-base; 3-base gasket; 4-base cuff; 5-washer; 6-spring inlet valve; 7-inlet valve; 8-seat inlet valve; 9-case; 10-equalizing piston; 12-piston ring; 13-gasket for the middle part; 14-middle part; 15-cover gasket; 16-cover; 17-spool; 18-tap handle; 19-nut; 20-cable; 21-pin connector; 22-controller cover; 23-cuff cover; 24-spring washer; 25-pin; 26-nipple; 27-filter; 28-reducer gasket; 29-plug; 30-spring of the feed valve; 31-feed valve; 32-saddle; 33-diaphragm; 34-props; 35-valve body; 36-adjusting sleeve of the reducer; 37-gear spring; 38-gearbox housing; 39-stabilizer; 40-cam; 41-ball bearing; > 42-axis; 43-spring; 44-panel; 45 microswitch

The valve gearbox consists of a body 26, an upper part with a pressed-in sleeve 25 and a body 29 of the lower part. In the upper part there is an excitation valve 24, pressed against the seat by a spring 23, which rests against the plug with its other end. A spring 30 acts on the metal diaphragm (membrane) 27 with a diameter of 78 mm from below through the support washer 28, abutting through the centering washer 32 against the screw 31. The reducer serves to maintain a certain pressure in the equalizing tank in the train position.

Driver's crane controller conv. No. 395-000 consists of a disc 4, two microswitches 5, a cam 3 put on a square of a rod 1, a tap handle 2 and a four-core cable 6. The force from the cam is transmitted to the switch button 5 through the ball bearing, the holder 8 on the axis 7 and the flat spring 9. At the bottom right is a diagram of the wiring of the switches 6 of the controller and the plug 5 of the plug connector conv. No. 354. Wire 1 is unmarked. The rest of the wires are colored: 2 - red paint; 3 - green; 4 - black. Wires are connected: 1 - to the power supply (positive); 2 - to the stall valve relay (free), which is not currently used in the electro-pneumatic brake system; 3 - to the release valve relay (terminal O of the control unit); 4 - to the brake valve relay (terminal T of the control unit).

5. Panels of the crane operator

a - No. 395-3; b - No. 395-4; c - No. 395-5

6. Wiring diagrams of controllers and
valve micro-switch positions

a - No. 395; b - No. 395-4; c - No. 395-5; d - No. 395-3

7. Spool ports and holes

8. Channels and holes of the mirror

9. Work of the crane driver
I position "Charge and leave"

Compressed air from the main reservoirs (GR) enters the brake line (TM) and the equalizing reservoir (UR) in two ways simultaneously.

In the UR 1 way - through the cavity above the spool, the hole in it (5 mm in diameter) and the cavity above the equalizing piston;

2 way - through the cavity under the spool (3 mm in diameter), a recess in it - to the feed valve of the gearbox and then into the cavity above the equalizing piston.

In TM, 1 way - through the cavity under the spool, the channel in it (diameter 16 mm) and further into the TM;

2 way - with an increase in pressure above the equalizing piston, it will move down (by 2.01-3.03 mm (from the middle position)) and open the two-seat valve with its shank. Air from the GR through the two-seat valve will begin to flow into the cavity under the equalizing piston and then into the TM.

With the I position, it is possible to recharge the UR and TM up to the GR pressure. Charging at this position is approximately 50% faster than at the II position of the RKM.

Main parameters of the balance piston and diaphragms

II position "Train"

There is no direct connection between the UR and the TM through the spool with the GR. By means of a recess in the spool, the air from the gas valve fits into the cavity above the reducer valve.

In this position, the crane has three operating modes:

1 - when the RCM is transferred from position I to position II, the elimination of supercharged pressure from the UR begins through the open valve of the stabilizer and a hole with a diameter of 0.45 mm. The equalizing piston rises (ideal TM) and through the open double-seated valve releases air at the same rate from the TM. With a real train, in which there are leaks, the equalizing piston, due to a greater decrease in pressure under it, lowers and vice versa does not allow the TM to discharge quickly and the brakes do not come into action.

2 - charging UR and TM to train pressure. While the pressure in the UR = 0 or less than the charging one (to which the reducer is adjusted) in the cavity above the diaphragm of the reducer, the pressure is the same as in the UR and under the action of a constant force of the regulating spring the diaphragm of the reducer is bent upwards and the supply valve is open. Compressed air from the GR through the cavity under the spool and the open valve of the reducer enters the cavity above the equalizing piston and then through the calibrated hole with a diameter of 1.6 mm into the UR and the cavity above the diaphragm of the reducer until the air pressure exceeds 0.05 kgf / cm² spring forces. After that, the diaphragm will bend down and the feed valve will close, blocking the access of air to the UR. At the same time, the pressure in the cavity above the equalizing piston increased and the piston moved down due to the pressure difference and opened the two-seat valve. Air from the HG will begin to flow into the cavity under the equalizing piston and into the TM until the pressures in the UR and TM are equalized and the piston takes the middle position (overlapping).

3 - automatic maintenance of the charging pressure in the UR by a reducer. Due to air leaks in the UR or through the stabilizer into the atmosphere, the pressure in the UR decreases and, under the action of the regulating spring, the feed valve of the reducer opens, ensuring constant train pressure in the UR. Due to the pressure difference in the cavities above and below the equalizing piston, it will constantly "oscillate" between the middle and lower positions, providing the same pressure in the UR and TM.

III position "Overlap without power"

On the spool mirror, all channels except one (4 mm in diameter), in which the check valve is located, are closed by a spool. In case of leaks into the TM, compressed air from the UR through the check valve, a hole in the spool with a diameter of 4 mm flows into the cavity under the equalizing piston. The pressure above and below the piston is equalized and it remains in the middle position. The two-seat valve is closed and there is no recharge for air leaks into the TM from the GR. This position is debilitating.

Used by:
1. to check the integrity of the TM;
2. to equalize the pressures of the head and tail of the train;
3. for use with EPT after braking.

IV position Overlap with power supply

All channels of the spool and mirror are closed, which means: the UR and the cavity above the equalizing piston are a closed volume with constant pressure. Due to air leaks in the TM, the equalizing piston moves down and opens the inlet valve, thereby feeding the TM leaks from the GR. This provision is inexhaustible.

Used by:
1. to check the density of the UR;
2. to ensure the direct action of the brakes;
3. to seat the equalizing piston in the middle position after braking.

VA position "Service brake
in long-piece freight trains at a slow pace "

In order not to break a long-train train when braking, it is necessary to reduce the pressure at the slowest pace (0.5 kgf / cm² in 15 - 20 seconds). As a result of the pressure drop in the cavity above the equalizing piston, the latter moves upwards and at the same rate releases air from the TM.

V position "Service brake"

It is achieved by communicating the UR and the cavity above the equalizing piston with the atmosphere through a channel in the spool with a diameter of 2.3 mm, which creates a discharge rate of 1 kgf / cm² in 4 - 6 seconds. As a result of the pressure drop in the cavity above the equalizing piston, the latter moves upward and at the same rate releases air from the TM. After moving the RCM from V to IV or III positions, the release of air from the HM to the atmosphere continues until the pressures in the UR and HM are equalized.

The process of discharging the UR during braking is accompanied by a decrease in the air temperature in it by about 5 - 9 C - this is at the stage of braking and by 17 - 19 ˚ C - with full service braking. After setting the RCM to position IV, the air temperature in the UR is equalized to the temperature of its walls, which leads to an increase in pressure in the tank: by 0.05 - 0.1 kgf / cm² after a stage and by 0.2 - 0.3 kgf / cm² after a full service braking. This process is called the thermodynamic effect.

VI position "Emergency braking"

UR and TM are connected to the atmosphere in all possible ways (by two ways UR and two ways TM). Since the volume of the UR is less than TM, the cavity above the equalizing piston is discharged faster than the cavity under it. The equalizing piston passes its entire upward stroke (4.5-6.09 mm), opening the exhaust valve as much as possible, and the TM is discharged to zero in the second way (the first way through a hole and a recess with a diameter of 16 mm in the spool. (The same hole works in position I, communicating GR with TM)).

10. Possible malfunctions of the 395 crane, arising along the route,
and recommendations to the locomotive crew for their elimination.

2nd position of the RCM

1. In the 2nd position of the RKM, the pressure in the UR decreases, and in the TM, on the contrary, it grows - a break, disconnection of the tube to the UR or destruction of the diaphragm of the reducer.
1.1. When the tube is broken or disconnected to the SD. if its tightness cannot be quickly restored, then order an auxiliary locomotive.
1.2. In case of destruction of the gearbox diaphragm (air is blowing from the hole in the adjusting screw), in order to get to the nearest station, you need to briefly put the RCM in the 2nd position and again put it in the 4th position. At the nearest station, at the 4th position of the RKM, change the gearbox to a serviceable one, taking it from an inoperative cabin.

2. In the 2nd position of the RCM, the pressure in the UR does not change or slowly decreases, and in the TM the pressure increases - the 1.6 mm hole or any other holes in the spool or its mirror intended for charging the UR are clogged.
After the train stops, change the upper and middle parts of the crane, taking them from the non-working cabin.

3. In the 2nd position of the RKM, the pressure in the UR and TM increases - the ingress of dirt particles or jamming of the reducer valve, violation of the spool density, as well as weakening of the RKM on the rod or working out along the square of the rod, clogging of the atmospheric hole 0.45 mm in the stabilizer.
3.1. Set the RCM to the 4th position.
a) if the pressure in the UR and TM stops growing, then the reducer may be faulty. You can get to the nearest station by alternating positions 2 and 4, and also: in the 2nd position of the RKM, by lightly tapping on the gearbox cap, you can remove a particle of dirt that has got under the valve, increase the rate of liquidation over the charge with a stabilizer, or by loosening its cap, cause an additional small leak from the UR ... At the nearest station, at the 4th position of the RKM, change the gearbox to a serviceable one, taking it from an inoperative cabin.
b) if the pressure in the UR and TM does not stop growing, it means that the malfunction is caused by a leaky spool, the overpressure can be prevented by the methods specified in paragraph a). At the nearest station, change the upper and middle parts of the crane, taking them from the inoperative cab.
c) when weakening the RCM on the rod or its development along the square of the rod, it must be manipulated carefully, given that the spool cannot be brought to the 2nd position.
3.2. If the atmospheric hole 0.45mm in the stabilizer is clogged (there is no air leakage through it), try to clean it. If this cannot be done, then a further increase in pressure in the UR and TM can be prevented by the methods indicated above. At the nearest station, at the 4th position of the RCM, change the stabilizer to a serviceable one, taking it from an inoperative cockpit.

4. Understatement of pressure in the UR and TM at the 2nd position of the RKM - clogging of the gearbox filter or strong ruptures in the sealing lip of the equalizing piston.
4.1. Stop the train. Leave the RCM in the 4th position.
4.2. If the pressure in the UR does not drop, it means that the gearbox filter is clogged. Remove the gearbox and its gasket, unscrew the filter with a screwdriver, remove the mesh from it and rinse it or burn it
4.3. If the pressure in the UR begins to fall, it means that the sealing lip of the equalizing piston is torn, it is necessary to replace it by taking it from the inoperative cabin.

5. At the 2nd position of the RKM at the end of the elimination of overcharge, there is an abrupt decrease in pressure in the UR, as a result of which the train brakes are triggered - low sensitivity of the stabilizer and the equalizing piston.
5.1. To get to the nearest station, you need to loosen the stabilizer adjusting spring, thereby reducing the rate of elimination of overcharge, and at the end of elimination of overcharge, close the 0.45mm hole with your finger and, after eliminating the residual overcharge, smoothly open this hole through the balancing piston sealing collar.
At the nearest station, disassemble the valve, wipe the equalizing piston and the bore in the housing for it, remove the valve from the stabilizer and wipe its shank and housing, as well as the bushing under it. Apply grease and reassemble the valve and stabilizer.

6. In the 2nd position of the RCM, air leaks through the middle choke of the lower part of the valve are accompanied by noise, while the density of the TM worsens - the balancing piston shank does not fit tightly to the outlet valve seat, the inlet valve does not fit tightly to its seat, the collar on the outlet valve shank is not tight.
6.1. If possible, follow to the point of changing locomotives.
6.2. If this is not possible (due to a sharp deterioration in the density of TM), then stop the train at the nearest station along the way. Disassemble the valve, wipe the balance piston shank and its seat in the outlet valve and apply grease. If after that the air leakage does not stop, then the leakage is due to the leakage of the intake valve to its seat or the leakage of the cuff on the tail of the exhaust valve. In this case, unscrew the atmospheric pipe from the middle fitting of the lower part of the valve, unscrew the base and remove the valve. Wipe the valve and bushing in the body underneath and apply grease. Take the base, which contains the sealing collar of the exhaust valve shank, from the inoperative cab.
At the 2nd position of the RKM, the slow elimination of the overcharge from the SD, which cannot be adjusted, is the passage of the reducer valve.
In the 4th position of the RCM, unscrew the reducer cap, remove the valve, wipe it and the sleeve under it, apply lubricant.
At the 2nd position of the RKM, a sharp drop in pressure occurs in the TM - a rupture of the rubber gasket between the lower and middle parts of the crane due to weak or uneven tightening of the nuts, since it is inconvenient to tighten the nuts near the wall of the driver's cab without a special key; as a result, squeezes the bridge in the gasket between the cavity above the equalizing piston and the atmospheric channel

7. It is necessary to change the gasket between the lower and middle parts of the valve, tighten the nuts evenly, you can also chalk the rubber gasket in a narrow place.

8. In the 2nd position of the RKM there is no elimination of the supercharged pressure from the UR - the stabilizer valve is stuck, the 0.45mm atmospheric hole in the stabilizer is clogged. At the nearest station, at the 4th position of the RCM, change the stabilizer to a serviceable one, taking it from an inoperative cockpit.

9. After the transfer of the RKM from the 1st to the 2nd position, the elimination of supercharging in the UR occurs very quickly, the brakes are activated in the train - the destruction of the stabilizer diaphragm.
Stop the train, at the 4th position of the RCM, change the stabilizer to a serviceable one, taking it from the inoperative cabin.

10. In the 2nd position of the RKM, the rapid elimination of overcharge in the UR is not amenable to adjustment, and in the 4th position, the pressure in the UR decreases - air leakage along the UR itself, or its tube to the driver's tap or pressure gauge, skipping the balancing piston cuff, skipping spool valve.
10.1. if, when traveling with a train, there is a strong understatement of pressure in the UR in the 4th position of the RKM, then follow to the nearest station, while releasing the brakes after the train stops completely.
10.2 At the nearest station, disconnect the TM between the locomotive and the train.
10.3. To disrupt the EPC, while setting the RCM to the 4th position:
a) If the pressure in the UR starts to drop, it means that the balancing piston cuff is damaged. In this case, lubricate it or replace it by taking it from the inoperative cab.
b) If the pressure in the UR does not drop, it means that air can pass through the spool. In this case, replace the upper and middle parts of the crane by taking them from the inoperative cab.
c) if this does not help, then follow to the point of changing the locomotive crews, while performing all braking until a complete stop.

11. In the 4th position of the RKM, the pressure in the UR and TM is overestimated - poor grinding of the spool to the mirror.
Avoid overpressure in the UR, using position 5A. If necessary, change the upper and middle parts of the crane by taking them from the non-working cab.

12. After braking, when the RCM is set to the 3rd position, the pressure in the UR rises - the check valve is passed in the middle part of the valve.
Use only the 4th provision of the RCM ..

13. Following on the EPT at the 3rd and 4th positions of the RCM, the lamp "P" does not light up or at 5A, the 5th and 6th positions, the lamp "T" does not light up - a large pitching of the RCM on the square rod, loosening of the microswitches or their shift on the panel.
When parked, remove the cover of the crane controller, fix the RCM and cam washer on it, fix the microswitches. If the operation of the EPT is not restored, switch to the pneumatic brakes.

5th position of the RCM.

1. At the 5th position of the RCM, the pressure decreases slowly in the UR and TM or does not decrease at all.
1.1. If an emergency stop is not required, then proceed to the nearest station, if necessary, order an auxiliary locomotive.
1.2. At the station, disconnect the TM between the locomotive and the train.
1.3. Set the RCM to the 4th position and disrupt the EPC:
a) If the pressure in the UR does not drop, then the 2.3mm hole in the spool is clogged. In this case, replace the upper and middle parts of the crane by taking them from the non-working cab.
b) If the pressure in the UR starts to drop, it means that the balancing piston cuff is damaged. In this case, lubricate it or replace it by taking it from the inoperative cockpit.

2. At the 5th position of the RCM, the pressure in the UR decreases normally, and in the TM it slowly or does not decrease at all - the 1.6 mm hole in the middle of the valve is clogged, the equalizing piston is stuck or frozen or its shank is broken, and, possibly, the atmospheric middle fitting pipe at the bottom of the valve.
2.1. At the station, replace the upper and middle parts of the crane by taking them from the inoperative cab. Remove the equalizing piston, inspect it and the bore in the housing for it, inspect the sealing lip, if necessary, replace it by taking it from the inoperative cabin and apply grease to these surfaces. Unscrew the atmospheric pipe from the middle fitting at the bottom of the valve. If during inspection it is found that the shank of the equalizing piston has broken off, then try to replace the piston by taking it from the inoperative cab. Possibly, after this the normal operation of the crane will be restored.

3. At the 5th position of the RCM, the pressure in the UR does not decrease, and the TM is discharged to 0 - freezing of the tube to the UR.
Perform braking by short-term RKM settings in position 5A. At the nearest station, where the pipe to the UR is warmed up and well blown through the driver's tap.

4. At the 5th position of the RKM, the pressure in the TM quickly decreases, after the transfer of the RKM to the 4th position, it grows rapidly, - flattening or partial freezing of the tube to the UR, as well as narrowing its flow area by a gasket at the point of connection to the tap.
When braking, the RCM must be kept in the 3rd position for some time so that the delayed air from the UR does not accumulate in the cavity above the equalizing piston, after which it must be transferred to the 4th position.

5. At the 5th position of the RKM, the pressure in the TM decreases by a much greater value than in the UR, and after installing the RKM in the 4th position, the pressure in the TM rises abruptly - low sensitivity of the equalizing piston.
5.1. If an increase in the pressure in the TM is detected after its increased discharge, it is necessary to immediately transfer the RKM from the 4th to the 3rd position, and before the prohibiting signal, make an emergency braking.
5.2. Disassemble the valve, remove the equalizing piston, clean it and the bore in the housing for it, inspect the sealing lip, apply grease to these surfaces. If necessary, replace the cuff by taking it from the inoperative cab.

11. Checks of the crane driver No. 395

1. Sensitivity of the driver's crane to the TM power supply.
Insert the tool with a 2mm diameter head into the end sleeve and open it. In the 2nd position, the driver's crane must maintain the pressure in the TM (+ -) 0.15 kgf / cm2.

2. Sensitivity of the equalizing piston.
When the pressure in the surge tank is reduced by the 5th position of the tap handle by 0.2-0.3 kgf / cm2, a corresponding discharge in the TM should occur.

3. Density of the surge tank.
A decrease in pressure when the valve handle is in the 4th position is allowed by no more than 0.1 kgf / cm2 for 3 minutes.

4. The rate of service discharge.
During service braking by the 5th position of the driver's crane handle, the time for reducing the pressure in the TM from 5 to 4 kgf / cm2 should be within 4-6 seconds. In the 5 (A) position of the operator's valve handle, the time for the pressure drop in the surge tank from 5 to 4.5 kgf / cm2 should be 15 -20 seconds.

5. Rate of emergency discharge.
The decrease in the pressure in the line by the 6th position of the valve handle from 5 to 1 kgf / cm2 should occur in no more than 3 seconds.

6. Rate of elimination of overcharge.
The pressure drop in the UR at the 2nd position of the tap handle from 6.0 to 5.8 kgf / cm2 should occur in 80-120 seconds.

7. In the 4th position of the valve handle, the pressure in the surge tank must not increase.
After discharging in the equalizing tank by the 5th position of the tap handle at 1.5 kgf / cm2 and moving the tap handle to the 4th position, the overpressure in the TM should not be more than 0.3 kgf / cm for 40 seconds.

8. The charging time in the 2nd position of the TM crane handle from 0 to 5 kgf / cm2 should take 3-4 seconds.

9. Charging time in the 2nd position of the balance tank valve handle from 0 to 5 kgf / cm2 should take 30-40 seconds.

10. Check valve check.
When the valve handle is set to the 3rd position (shut off without power supply) and the valve is opened on the main line with an opening with a diameter of 5 mm, the pressure in the TM and the surge tank decreases continuously.

11. The density of the surge tank and the time to eliminate the overcharge pressure when the locomotive is released from the depot after repair and maintenance (except for TO-1) should be checked if the TM of the locomotive leaks through the 5mm hole.

12. Checking the force of movement of the KM handle:
- set the point of application of the dynamometer at a distance of 200 mm from the axis of the rod;
- with an air pressure on the spool of at least 8.0 kgf / cm2, the effort to move the handle between positions should not exceed 6 kgf; the effort of moving the handle through the protrusions or depressions on the gradation sector of the valve body should not exceed 8 kgf.

13. When releasing the locomotive from the depot, check the air flow through the blocking device No. 367 and through the driver's crane. The check is carried out at an initial pressure in the GH of at least 8 kgf / cm and the compressors turned off. Decrease in pressure in a GH with a volume of 1000 liters from 6 to 5 kgf / cm2. The blocking permeability is considered normal if, when the driver's crane handle is in the 1st position and the TM end valve is open from the side of the tested device, the pressure drop occurs in a time of no more than 12 seconds.
TEM2, TEM18, ChME3 - 12 sec.
2TE10M - 25 sec,
VL80 - 22 sec.
2TE10U - 27 sec.

Literature

METHODOLOGICAL DEVELOPMENT
On the topic "Driver's crane conv. 395"