On Mon, 11 Mar 2019 20:09:46 -0000, newshound wrote:

On 11/03/2019 15:52, Martin Brown wrote:
On 11/03/2019 15:46, Commander Kinsey wrote:
On Mon, 11 Mar 2019 15:28:57 -0000, Andy Burns
wrote:

Commander Kinsey wrote:

hat are those things you see in the middle of nowhere (in the UK at
least), a 10 foot high white pole with an orange roof-shaped lid on
top?

Hi-viz poles to allow the chopper to follow the pipeline route easily.

They're not just markers, I'm sure they can actually let off gas.

They are simple makers for the helicopter that checks the pipeline to
follow with its airborne leak checker. One of the high pressure
pipelines runs close to me. They also mark the no dig zone at the
roadside (permission required from the pipeline owner Ineos or Shell).

+1.

In the old days, there were tall vent stacks for sewers. Cast iron with
nice "petals" at the top, about the height of a telegraph pole. In urban
areas.

As a kid, did you ever climb one and block it?