Dave Liquorice wrote:
On 4 Aug 2019 19:04:59 GMT, Tim+ wrote:

Why not syphons? I mean, pumps use power, quite a lot of it and are
relatively expensive.

The Fire and Rescue service high volume pumps are part of the
national reslience system. Seems there are 51 dotted about the
country to be called upon locally or nationally as required. Each one
is capable of delivering 7,000 litres per minute (enough to meet the
demand of up to three fire engines all running flat out) over several
km of hose. They are floating "sump pumps", the small red boxes in
the water in some of the pictures. Seen reported that 16 of these are
in use. The same pictures also reveal larger yellow pumps, presumably
commercial pumps of even higher capacity.

The coverage of these "technical" details is sadly lacking. Most
people won't have any idea of the size of pipes and speed of flow
that shifting that volume of water requires.

I see under the scheme that you mention our Brigade, Hampshire has deployed
some resources.
They have some pumps in their inventory that are intended for use on ships
in in the ports of the county
which are a type of ejector pump with no moving parts into which high
pressure water is pumped.

I have witnessed some in use on exercise with where they emptied the
ballast tanks of a ship using it,
it seems strange to see water pumped into a space you want to empty of it
but more is removed than is being pumped in by quite a percentage using the
Venturi effect .

They are mentioned in this document around page 46.

https://www.ukfrs.com/sites/default/...Supplies.pd f


The lack of moving parts is a great advantage especially in a ships hold
where floating debris could jam or damage a mechanical one, one of the
pumps uses is to pump water accumulating within a hull from shoreside hoses
deployed on a fire as by the time you bring a fire under control may have
sunk or destabilised the ship.

ICBW but I think at one time the version they used was known as the
Southampton Ejector Pump as it was developed by the brigade in that city
(town at the time) due to the large amount of dock estate they cover.

GH