Pneumatics

Question 1

What equipment runs on compressed air? (7)

Answer 1

Main Reservoirs
Auxiliary Reservoirs
Air Suspension Reservoirs
Surge Reservoirs
Whistle
Friction brakes
Spring Park brake

Question 2

What pressure does the Compressor Governor / Compressor Pressure Switch maintain the Main Reservoir at?

Answer 2

850 - 1000 kPa

Question 3

What pressure are the Safety Valves set at?

Answer 3

1100 kPa - between compressor and air dryers

1050 kPa - between air dryers and Main Res.

Question 4

What happens if the Compressor Pressure Switch (CG) is isolated?

Answer 4

The air compressor will run continuously

Question 5

What is the air suspension system made up of? (3)

Answer 5

Levelling valves

Air bags

Surge reservoirs

Question 6

What do the Levelling Valves do?

Answer 6

They Inflate or deflate air bags according to passenger load

On DM Cars: One on each bogie.

On T Cars: Two on No.1 Bogie, 1 on No.2 Bogie

Question 7

What happens if air bags fail?

Answer 7

There is a spring system as well.

Question 8

What do the Surge Reservoirs do?

Answer 8

Supply air to the air bags to compensate for:

Train tilting around corners
Uneven passenger load
Sudden imbalance in suspension system

Two surge res. per bogie

Question 9

What is the Brake System comprised of?

Answer 9

Service Brake (Friction
Holding Brake
Emergency Brake
Park Brake

Question 10

What is the Service Brake made up of?

Answer 10

ED

EP

Question 11

When does the ED Brake work?

Answer 11

Normally, above 10kmh

Between 5-10kmh. brake blending occurs

Question 12

What happens during wheel slide?

Answer 12

ED brake drops out and EP brake takes over

Question 13

What is the EP brake used for?

Answer 13

Stopping at low speeds when ED brake fades out

Assisting ED brake during heavy high-speed braking

Supplementing braking demand when effort provided by the ED system is insufficient

Question 14

What happens if ED brake fails?

Answer 14

EP brake will automatically take over

Question 15

What kind of brakes are on TCars?

Answer 15

EP brakes only

Question 16

When does the Holding Brake apply?

Answer 16

when MCH is in 0 (coast) when train is stationary.

Question 17

What is Holding Brake pressure?

Answer 17

110 kPa (+/- 30 kPa)

Question 18

When does Holding Brake pressure release?

Answer 18

When traction power is applied

Question 19

What happens if train is stationary and and a different braking position is selected (B1-B6)

Answer 19

The corresponding braking pressure will be applied

Question 20

What is B6 (Full Service) pressure?

Answer 20

189 kPa

Question 21

What is Emergency pressure?

Answer 21

280 kPa (+/- 30kPa)

Question 22

What is Main Res operating pressure?

Answer 22

850-100 kPa

Question 23

What happens if MCH is moved to B1, B2 or B3 when the train is on a gradient?

Answer 23

B1-B3 pressure are below Holding pressure so the train may roll

Question 24

What must you do with BCH when moving between braking and powering?

Answer 24

Remain at ZERO/COAST for 1 second to allow TCU/BCU time to set up

Question 25

What fault lights come up when Service Brake is applied?

Answer 25

Maintenance Fault Light General Fault Light They will flash and should not be considered a train fault

Question 26

What brakes are used during emergency braking?

Answer 26

Friction brakes only

Question 26

When do SPBs apply?

Answer 26

Automatically when Master Key is turned to OFF Automatically applies when Main Res. pressure falls below 350 kPa Park Brake Switch in drivers cab illuminates if one SPB is applied

Question 27

Where are SPBs located?

Answer 27

Wheels 3 and 7 on every car

Question 28

Can SPBs be manually released?

Answer 28

Yes Manual release device located on each side of every bogie

Question 29

Which SPB is locked?

Answer 29

Number 1 Bogie

Question 30

What happens if the SPB is applied with the train speed over 5kmh?

Answer 30

Safety Loop will de-energise and emergency brakes will apply Reset Safety Loop by placing MCH into ZERO

Question 31

What is procedure to manually release SPB?

Answer 31

Isolate the Bogie Pull the handle to release SPB Reinstate Bogie

Question 32

How does the Brake System work?

Answer 32

MCH sends electrical signal to BCU which then processes input and applies/releases brakes through the Brake Module on each bogie accordingly

Question 33

What does the braking system consist of? (5)

Answer 33

BCU (one per car) Brake modules (two per car) Brake Cylinders (every wheel) Parking Brake Cylinders (Wheels 3 and 7) Associated ICs

Question 34

What does the BCU do?

Answer 34

It's an electronic microprocessor that receives and interprets signals from various sources to determine ED/EP braking requirements

Question 35

How are BCUs on DM different to those on TCars?

Answer 35

DM BCUs operate in conjunction with TCU On trailer cars, there is no ED braking and no TCU

Question 36

What information does the BCU use to work out braking requirements? (4)

Answer 36

Load/weight (from secondary suspension) Speed (from pulse generators on each axle) ED brake information (from TCU on a DM car) Wheel slip protection

Question 37

Which isolating cocks do we need to know in the Brake Modules ?

Answer 37

Top - air suspension Bottom - bogies

Question 38

How does the TCU manage wheel slip?

Answer 38

When ED braking effort falls below 90% TCU drops ED and EP takes over Sanders automatically dispense

Question 39

How do you reset EP to ED during wheel slip?

Answer 39

If safe, move MCH to 0 or a powering position for one second then return to desired braking position

Question 40

What is each sand box equipped with?

Answer 40

Padlock RED LED illuminates if sand is below 20% White manual test button Sight glass to see dryness of sand

Question 41

When do sanders operate?

Answer 41

Only during EP braking Not powering or ED

Question 42

What speed do sanders operate at?

Answer 42

Stop working below 5kmh