What does "Desilt And Cabling" mean?

there are roadworks outside parents house. Their exchange is getting fibre in December and they have roadworks outside their house saying"desilt and cabling for BDUK" what does it mean?

Clearing the silt from the cable ducts I would say so they can run the fibre.

i.e. cleaning and unblocking them

exactly, jet washing the cr&p out

And with the winter storms and flooding last year even ducting cleared the previous year could well be all silted up

I'd hope that if ducting has been recently cleared for fibre, that they'd have run a lot of spare sub-ducts (essentially plastic tubes), so that they can blow more fibre through without having to clear the ducts again.

It's one of these cabs. All the fibre work is being done now and then on website it says will be able to order from ISP's by June 2015!

The standard black with yellow stripe tube carries numerous sub ducts http://www.coolwebhome.co.uk/fibre-milton-keynes/wgc...

Believe the ducting roll-out is scaled to serve the cabinets from the aggregation node and also any subsequent FTTP build, either FTTPoDemand, or native FTTP if the decision is taken in the future, or to support FTTrN. Use of GPON for FTTP reduces fibre count

http://www.coolwebhome.co.uk/fibre-milton-keynes/wgc... fibre blowing rig (indoors for demo)

http://www.coolwebhome.co.uk/fibre-milton-keynes/wgc... individual fibre cores

http://www.coolwebhome.co.uk/fibre-milton-keynes/ the full set.

What would prevent the sub-ducts silting up?

Surely the sub-ducts would be tubing and be inside the main duct meaning even if the main duct silted up, they'd be unaffected.

Only if the sub ducts were sealed. I am assuming as it is possibly to pull additional fibre through them that they aren't sealed in which case there most be places where silt and other blockages can enter from?