What technology could be used to check if a line is clear?

[Technologist]

Not in the middle of the storm, but there is a sizeable window between the winds slowing enough for further tree fall being very unlikely and allowing drone flight.

There is also stuff like visual SLAM which allows a drone to do stuff like fly through a forest at speed dodging out of the way of branches. We're not talking about hand flown quad copters, potentially we could have a fixed wing drone flying below the OHLE at rail vehicle velocities and being capable of flying in pretty strong winds.

If it spots something it slows to hover bourne lift speeds and does a survey. The route proving train can proceed straight to that point at higher speed or a crew can go by road if closer.

 

[DerekC]

There is also stuff like visual SLAM which allows a drone to do stuff like fly through a forest at speed dodging out of the way of branches. We're not talking about hand flown quad copters, potentially we could have a fixed wing drone flying below the OHLE at rail vehicle velocities and being capable of flying in pretty strong winds.

If it spots something it slows to hover bourne lift speeds and does a survey. The route proving train can proceed straight to that point at higher speed or a crew can go by road if closer.

Should be possible for a drone to follow the track at driver's eye level, then. Drone pilot five minutes ahead of the route proving train?

 

[Nottingham59]

I wonder if some use of modern technology could be considered.

I understand you can get high resolution satellite images of any point on Earth that can in principle be updated up to four times a day. No use in cloudy conditions, but might be feasible in some conditions.

 

[Winthorpe]

I understand you can get high resolution satellite images of any point on Earth that can in principle be updated up to four times a day. No use in cloudy conditions, but might be feasible in some conditions.

Yes, that's certainly the future. Either from space satellites or using pseudo-satellites (see below). I have read that the Ordnance Survey are very interested in this technology (see this BBC article about its 2019 investment in the Astigan high-altitude pseudo satellite) .

High-altitude platform station - Wikipedia

en.wikipedia.org

What I had in mind was something that would like footage taken from a helicopter. I did some research and that's not yet commercially available. It's only the military that do it from unmanned drones. It is a good idea for the future.

Edit: To add source for Ordnance Survey interest in pseudo satellite technology.

 

[Egg Centric]

Geostationary satellites with that radar wot looks through cloud should do it. Or bring Canberras out of mothball...

 

[Technologist]

Geostationary satellites with that radar wot looks through cloud should do it. Or bring Canberras out of mothball...

It's not geo-stationary satellites which use radar for mapping as the resolution would be terrible. Synthetic aperture radar satellites generally operate in constellations in polar orbit sweeping over every part of the globe regularly.

They basically pump out a continuous beam of radar and the movement of the satellite does the scanning.

 

[d9009alycidon]

John Anderson worked out how to do it, in 1883! Dare say it would work for fallen trees too.
"Anderson was secretary of the Callander & Oban Railway, and devised this system to detect rockfalls. As subsequently expanded, a total of seventeen semaphore signal pairs are linked to a screen of wires which, if broken, will return the signal arms to danger. The nickname derives from the whistling sound which is said to be made by the wind blowing through the wires.
The first length of screen was brought into use in January 1882. It was 1,112 yards (1,017 m) in length and there were four associated signals. In April 1883, the screen was extended at both ends, bringing its total length to 5,659 yards (5,175 m). The final extension, at the west end, was made in September 1913, increasing the length to 7,054 yards (6,450 m) - just over four miles (6.5 km). The system has defied replacement because modern computerised detectors are too sensitive. There was a second smaller installation at Craignaculloch by Loch Lubnaig on the eastern section of the line that closed in 1965"

 

[Bald Rick]

John Anderson worked out how to do it, in 1883! Dare say it would work for fallen trees too.
"Anderson was secretary of the Callander & Oban Railway, and devised this system to detect rockfalls. As subsequently expanded, a total of seventeen semaphore signal pairs are linked to a screen of wires which, if broken, will return the signal arms to danger. The nickname derives from the whistling sound which is said to be made by the wind blowing through the wires.
The first length of screen was brought into use in January 1882. It was 1,112 yards (1,017 m) in length and there were four associated signals. In April 1883, the screen was extended at both ends, bringing its total length to 5,659 yards (5,175 m). The final extension, at the west end, was made in September 1913, increasing the length to 7,054 yards (6,450 m) - just over four miles (6.5 km). The system has defied replacement because modern computerised detectors are too sensitive. There was a second smaller installation at Craignaculloch by Loch Lubnaig on the eastern section of the line that closed in 1965"

And it’s been a right pain ever since! Been broken most of this year, with resulting speed restrictions and some big delays.