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Thursday, 1 March 2012

Lighting trial in Combe Down Tunnel – 29 Feb 12

Lighting Services from Bristol conducted a trial to ensure that the 'essential' or 'basic' lighting being proposed for the tunnels would work in practice. United Visual Artists from London also visited to look at the tunnel environment and the refuges into which the feature lighting will be incorporated. The two teams discussed technical issues on how the two systems would work together. Select the image for a video report on the event.


Anonymous said...

Looks fantastic. Can't wait to ride through it.

Keep up the great works guys.

Matthew Holbrook said...

Thanks for the ongoing video record of the route's construction.

Anonymous said...

In the video, what's the beeping noise?

Anonymous said...

Nice mention of bats,if there are any !

franktompson said...

The beeping noise is a gas detector declaring all is well. (Mandated by h&s regulations at this stage as both doors were shut and a petrol generator was in use.)

Gerard said...

Nice work Frank! Do you have any more details of the lights in terms of cost, source, and power requirements? Also, could they be controlled by motion-activation?

We're looking for a similar lighting solution for the Caversham tunnel.


James said...

Great! A sense of progress. Looks very theatrical, with the matt-black ceiling. what a sensation it will be to travel through. keep it up!

Mark A said...

Thanks everyone for your comments and encouragement.

@Gerard: delay to the Two Tunnels project has had a silver lining, as it has given us the opportunity to use LED lighting in the tunnels - the technology for this has come on in leaps and bounds and we're really pleased about this.

The lights are 11 watts apiece, made in Europe, and will basically run submerged if they need to so will hopefully shrug off the tunnel environment.

The feed to them is at UK mains voltage.

They have a thin 'Letter box' window in a cast case and are designed so that the light goes only where it's allowed to - evenly onto the floor and tunnel walls to a height of about two metres, and contained within about a seven metre section.

An advantage of seven metre spacing is that the tunnel lights will not form a series of 'Pools' that are overbright in order to push enough light into the spaces between.

In the trial, the amount of light going elsewhere was minimal - including along the tunnel - and it was remarkable how, looking along the tunnel, the light was showing the path, the people - without every lighting unit sending light directly to the eye.

It would certainly be possible to switch them using sensors: I don't know if they're dimmable or not but the appropriate design of their electronics could make it so ...

Hope this helps and best wishes for the Caversham Tunnel project.

trikemaniac said...

Any idea as to whether the tunnel could be cycled through on Saturday 12 May ? We have an organised ride from Bristol to Salisbury on that day.

franktompson said...

Hi trikemaniac,

The tunnels are planned to open together, along with Tucking Mill Viaduct, in October, so no, afraid not available in May.

(Apologies for the late reply; we've had a technical hitch, now resolved.)

franktompson said...

With reference to bats it depends on the time of year, breeding patters etc. Lighting will be switched off between 11pm-5am to ensure that any bats present are not disturbed. Luminaires will be positioned well below the tunnel crown, and pointing downwards, as a further precaution. These measures are in accordance with professional advice received by Sustrans.

(Apologies for the late reply; we've had a technical hitch, now resolved.)