Slippery when wet

corblimey

Can anyone explain to me the science behind the fact that the tunnel gets wet when it's raining outside. I can sort of understand rain, etc being brought in car tyres and stuff, but yesterday morning after the few days of torrential rain, there were puddles building in the middle of the tunnel. Also, shouldn't the wetness kinda 'fade out' after a short distance, like when you drive through a puddle, there's tyre tracks but they stop as the wheels dry.

Jumpy

Water flows downhill.

corblimey

Jumpy wrote: »

Water flows downhill.

Seriously? There's enough surface water brought in on tyres and that to warrant a 'flow'?

Stark

Water falls from the sky. Then it flows downhill.

corblimey

Stark wrote: »

Water falls from the sky.

Witchcraft!

Actually, I suppose that makes sense.

deRanged

All the concrete/tarmac area catches water but doesn't let it drain. it has to flow down - so there's a huge surface area funneling water into the tunnel, both bores, both sides. Then cars are tracking it in, tens of thousands of cars remember.

dulpit

Jumpy wrote: »

Water flows downhill.

This ++;

What else could happen??? Of course it flows in, esp. with the amount of cars flying through too...

Tree

The drains have been known to back up in the tunnell too. Puddles w/ no apparent origin by drains.

corblimey

dulpit wrote: »

This ++;

What else could happen??? Of course it flows in, esp. with the amount of cars flying through too...

I guess I never considered the slope in and out of the tunnel to be steep enough for surface water to 'flow' in. But deRanged's explanation that there's nowhere else for the rain to go makes some sense.

Dee369369

Doesn't seem so steep when you drive through it but when i walked it the day they opened it(years ago now!) it's pretty steep.
Anyway what a weird thing to be thinking :D

Colonel_McCoy

Poor design!

chuci

why did they make it slanted in the first place?

Pi^2

why did they make it slanted in the first place?

Eh well. either side of the tunnel is above sea level, and tunnells tend to be resting on the sea bed. So naturally the tunnnel must go from x metres above sea level down to hte seabed and then back up to y metres above sea level on the otherside. Hence the curve.

mawk

Pi^2 wrote: »

Eh well. either side of the tunnel is above sea level, and tunnells tend to be resting on the sea bed. So naturally the tunnnel must go from x metres above sea level down to hte seabed and then back up to y metres above sea level on the otherside. Hence the curve.

Zing.