Was it safe to cross or not?

I think the reason for the crossing showing failed is that the low speed of the approaching train has exceeded the specified time for it to pass over the crossing. I'm not sure how that ties in to the 'Train passed' and 'Oi!' call logic.

This is to do with "roll-back protection" on the AHB. If a train sits on the strike-out track circuit for too long, the crossing logic (in real life) assumes the train may be rolling back and so lowers the crossing to warn road users. The flashing red lights trigger the "Oi" call.

It is normal to suppress roll-back protection if there's a operational reason for trains to stop on the strike-out track circuit (e.g. station immediately after the crossing) or rolling back is implausible (e.g. significant downwards gradient or catch points).

That previous explanation covers it. Note carefully that real AHBs behave like this: the SimSig logic is copied directly from the sample circuit diagrams in the Nock Red Book. It's not a deficiency in SimSig.

The farmer is phoning to complain because the red lights have started flashing and the barriers descending after you told her it was safe. I don't blame her.

I had a similar experience on the Oxted sim. I had a phone call from Hempstead UWC asking to cross, but I cant remember for sure what they wanted to cross with, I think it was a slow vehicle or an abnormal load. I had a train waiting to depart Uckfield and the call came about 10 minutes before departure time. Thinking that this should give enough time to cross I told them it was safe to cross. I was expecting the "crossing clear" call after about 5 minutes, but no call came and the train departed and passed the crossing. 12 minutes after I gave them permission to cross I got the "oi" call.

The crossing in question is a UWC, with neither barriers nor lights, hence why he had to phone me for permission to cross ...

ambergatesm in post 138620 said:

I had a similar experience on the Oxted sim. I had a phone call from Hempstead UWC asking to cross, but I cant remember for sure what they wanted to cross with, I think it was a slow vehicle or an abnormal load. I had a train waiting to depart Uckfield and the call came about 10 minutes before departure time. Thinking that this should give enough time to cross I told them it was safe to cross. I was expecting the "crossing clear" call after about 5 minutes, but no call came and the train departed and passed the crossing. 12 minutes after I gave them permission to cross I got the "oi" call.

Without a phone call I wouldn't have routed the train over the crossing at all. But how long do you leave it? If a reasonable amount of time passes and nothing has happened, you'd be tempted to contact the driver of the train and tell them to approach the crossing at caution and be prepared to stop, and to report in what they see there.

With no option for doing this exactly in Simsig, the closest thing we have is pass signal at danger and/or examine the line, but I don't know whether or not doing this would prevent the driver from wiping out an articulated lorry stuck on the crossing :)

I had to do something similar in real life at Parsonage Farm UWC crossing in the down direction, west of Castle Cary station. The farm workers there are usually very good at closing the gates behind them and calling the signaller. On this particular day someone had clearly forgotten to call to say the crossing was clear. I was stopped at the previous signal and told to approach the crossing at caution and stop to report if the gates were still open. I can't remember if I was authorised to pass the signal at danger or not. It's not a signal you want to have to pass at danger to examine the entire section ahead at caution, as it's almost nine miles to the next signal at Somerton!

I don't know if you are familiar with Oxted sim, but there are no signals at Uckfield. When a train is waiting to depart from Uckfield there is no way of stopping it. The train will depart at it's booked time regardless of whether a route has been set or not.

I don't know if you are familiar with Oxted sim, but there are no signals at Uckfield. When a train is waiting to depart from Uckfield there is no way of stopping it. The train will depart at it's booked time regardless of whether a route has been set or not.

ambergatesm in post 138624 said:

I don't know if you are familiar with Oxted sim, but there are no signals at Uckfield. When a train is waiting to depart from Uckfield there is no way of stopping it. The train will depart at it's booked time regardless of whether a route has been set or not.

There are a few other similar dead-end branches where the driver is required to phone for permission to depart in the absence of any other fixed signalling precisely because of that kind of situation (some of which might even appear in Simsig, Barnstaple e.g. if I remember correctly?), but it seems that Uckfield isn't one of them.

These days of course you can try getting hold of the driver via GSM-R at any time anyway, but how would things have been handled before that?

You wouldn't have been S5-ed just cautioned.

TUT in post 138625 said:

You wouldn't have been S5-ed just cautioned.

I realised that once I'd posted, but couldn't be bothered to edit it :)

And now I think about it, the signaller brought me down to a red signal at Castle Cary (I was stopping there anyway), called me on the GSM-R, and then cleared the signal for me to proceed at caution down to the crossing. The gates were closed, so somebody just forgot to call back.

[quote=ambergatesm;post=138624]Simsig doesn't simulate this action, so there's nothing to stop our train driver ploughing through a herd of sheep departing Uckfield ...

lazzer in post 138627 said:

[quote=ambergatesm;post=138624]Simsig doesn't simulate this action, so there's nothing to stop our train driver ploughing through a herd of sheep departing Uckfield ...

Hempstead crossing is less than a mile from the station. The train wouldn't have picked up that much speed. Especially since it is an uphill gradient.

Line speed is 30 towards Uckfield and 70 out of Uckfield.

But there is short sighting. So it is hard to tell if a train could stop in time.

http://abcrailwayguide.uk/hempstead-private-level-crossing-east-sussex#.YHhcZuhKiUk

I had a similar experience on the Oxted sim. I had a phone call from Hempstead UWC asking to cross, but I cant remember for sure what they wanted to cross with, I think it was a slow vehicle or an abnormal load. I had a train waiting to depart Uckfield and the call came about 10 minutes before departure time. Thinking that this should give enough time to cross I told them it was safe to cross. I was expecting the "crossing clear" call after about 5 minutes, but no call came and the train departed and passed the crossing. 12 minutes after I gave them permission to cross I got the "oi" call.

That previous explanation covers it. Note carefully that real AHBs behave like this: the SimSig logic is copied directly from the sample circuit diagrams in the Nock Red Book. It's not a deficiency in SimSig.

The farmer is phoning to complain because the red lights have started flashing and the barriers descending after you told her it was safe. I don't blame her.

clive in post 138619 said:

That previous explanation covers it. Note carefully that real AHBs behave like this: the SimSig logic is copied directly from the sample circuit diagrams in the Nock Red Book. It's not a deficiency in SimSig.

The farmer is phoning to complain because the red lights have started flashing and the barriers descending after you told her it was safe. I don't blame her.

How do we know it was a woman?

an irate farmer telling me that he thought I said it was safe to cross.

Hempstead UWC may be quiet in real life, but on the sim it can be busy with abnormal loads, slow vehicles, herds of cows, flocks of sheep and even a gaggle of geese. I think I will play it safe in future and make them wait if a train is at Uckfield and risk the "No sign of a "b----y" train call. With regard to Late Turn's comments about the Matlock branch, there are no track circuits between Ambergate and Matlock, so the signaller will not know where the train is. The guard does report when the train arrives at Matlock, but I think it is to control. In the Derby PSB sim the progress of the train is shown in the Train list. I travelled regularly on the branch before lockdown, and although I have seen tankers in the sewage works, I haven't seen one waiting to enter.