Low adhesion

Question 1

what can cause low adhesion?

Answer 1

leaves
damp conditions
factories
sea salt
light rain following dry periods
vehicles at level crossings

Question 2

what is wheel slip?

Answer 2

where train wheels cannot grip when trying to start moving

Question 3

what is wheel slide?

Answer 3

where wheels lock up completely

Question 4

what type of trains have an increased risk of slip/slide and why?

Answer 4

disc brakes as they make no direct contact between brake block and wheel to clear contaminants

Question 5

when is official leaf fall season?

Answer 5

1st october to 24th december

Question 6

if you experience serious bad low adhesion how can you let your depot know?

Answer 6

ask conductor to call ahead

Question 7

what should entires on low adhesion board include?

Answer 7

exact location
conditions
time

Question 8

what do metdesk do?

where are they posted the warnings?

Answer 8

discuss railhead conditions across the network to form an adhesion warning that is published in notice cases

LNC

Question 9

what does a red warning mean?

Answer 9

poor adhesion and high risk

Question 10

what does black warning mean?

Answer 10

very poor adhesion, extreme caution required

Question 11

where can historic low adhesion areas be found?

Answer 11

sectional appendix or permanent notice case

Question 12

what questions can you ask yourself to judge the conditions ?

Answer 12

are you the first train over it?
has it been treated?
weather conditions ?
railhead appearance ? black or silver
LNC metdesk notices ?
what brakes you have on your train?

Question 13

how is contamination categorised ?

Answer 13

level 1 - lots of silver
level 2 some silver
level 3 no silver

Question 14

how often would you carry out RBT in low adhesion?

Answer 14

more than usual

Question 15

when does automatic sander operate?

Answer 15

when WSP activity is detected and sand in emergency (on a 150/1)

Question 16

where should you avoid placing sand?

Answer 16

over points, switch diamonds and swing noses

Question 17

how should you try and prevent wheel slip when setting off?

Answer 17

take power is lower notches

Question 18

how would you know your in a slip?

in a wheel slide?

Answer 18

speedo may fluctuate and WSP light will illuminate

speedo may drop to zero

Question 19

how should you act if in a slide and brake not doin anything?

Answer 19

allow WSP to take place and slow down if not doing anything put into emergency

Question 20

what are reportable railhead conditions?
expected ?
good?

Answer 20

poor adhesion, worse conditions than expected
poor adhesion, no surprises
nothing to report

Question 21

what might the signaller ask the following train to do when received a reportable railhead adhesion?
how would you do this?
what would you do after this?

Answer 21

conduct a controlled test stop

brake the train normally for the environment and railhead conditions at that location

report findings to signaller and confirm conditions are reportable