Hose Layer vs High Volume Pump

[Rory-495]

Hi all,

Just wondering what people's opinions are/other brigades procedures when employing hose layers or high volume pumps?

My station has a HLU and in a year it's been out a few times but only (I think) laid the hose once. Conversely the neighbouring stations HVP goes out all the time and is used in favour of the HLU on multiple occasions given they show up at the same time usually.

On top of this, the rumour mill has been giving hints that LFB could be looking to get rid of HLUs in favour of the HVP; mainly because while the HLU can theoretically deploy a long (4KM single or 2KM twinned) 90mm hose very fast, it requires intermediate appliances to maintain pressure. So it's speed means nothing if you are waiting for appliances to finish the relay - whereas the HVP's 150mm hose has far less frictional loss and thus doesn't require the intermediate pumps.

So my questions are:

• What do other brigades use?
• Are any of you scrapping HLU?
• Does anyone in LFB know of any plans to be scrapping the HLU?

[Becile]

No hose layers for us, hvp and our normal appliance pumps ars higher rated, which supports the flow and possible requirement for higher pressures.  The intakes are also 150mm to take hvp inputs. You can also use 4 way adapters to utilse pumps within the hvp set up, also means you can fit in with national/regional support without having to crew your own specifically built hose layers ...cmon lfb get with the program...lol

 

[Rory-495]

All valid points and again makes me wonder what the advantages are of a HLU. Everyone states the deployment speed as the major advantage but if you are waiting for extra appliances it's not a benefit. Also a reasonably small job turns hugely manpower intensive if you have a lengthy relay

[Keith]

A perfect question for Carl methinks. ☺️

[Carl]

I thought I would sit back and digest the views of others before my two penneth

[Matt]

The number of dedicated hose laying vehicles or pod's has declined since the HVPU's were introduced, I do think each Brigade has their own now but stand to be corrected on that.

There are less than a handful with their own now and many have not been replaced as they have come of age, the exception is Shropshire who call theirs a major pumping unit which replaced some older versions of their own made HVPU's they had.  The LFB have the biggest fleet of HL's out of anyone (ignoring the HVPU).

Will always be a need in some form, look back to the green goddess's and the supporting pipe carrier trucks and their 6" hose and 8 way manifolds.

[Noddy]

HVP for me every time 👍

[Becile]

12 hours ago, Carl said:

I thought I would sit back and digest the views of others before my two penneth

Any negative comments will result in Carl paying back his wages...lol

[Mess6311]

Another one for Carl.

Having been at a HLL station previous and now finding myself back on one, is the advantage of HLL over HVP pressure fed supplies? HVP being better from open water sources? I have never worked HVP so dont know its capabilities. It does seem to be getting used more frequently in county where as previous it seemed to be ring fenced for national resilience, or at least that might just be my perception

[Rory-495]

I'm terms of using it on a pressure fed supply, we carry several standpipes and stirs coupling adaptors on the HLU and every pumping appliance just for the reason of connecting into a hydrant/appliance. The issue with 90mm hose is it becomes affected by frictional loss a lot sooner than a HVPU and requires less assistance in maintaining pressure. I'll look when I'm back in work at the actual processes but I believe this is the main reason the HVPU is taking precedence.

[HoldFast]

HVP in my opinion is superior to HLU and would probably take precedence every time where the volume of water required would warrant the use of either one.

[Mess6311]

4 hours ago, Rory-495 said:

I'm terms of using it on a pressure fed supply, we carry several standpipes and stirs coupling adaptors on the HLU and every pumping appliance just for the reason of connecting into a hydrant/appliance. The issue with 90mm hose is it becomes affected by frictional loss a lot sooner than a HVPU and requires less assistance in maintaining pressure. I'll look when I'm back in work at the actual processes but I believe this is the main reason the HVPU is taking precedence.

Ours carry 100mm hose (which i appreciate is still less than the HVP)

[Rory-495]

Is that the same as your pump inlet? Would make sense in terms of a water relay to go straight into the eye of the pump instead of into the tank-pump-deliveries as we do in LFB

[HoldFast]

Don’t ever go straight into the tank from the HVP or you’ll rupture the tank! Happened on a job I was on last year. The pump couldn’t keep up with the volume of water going in vs out and so the tank burst 😅

[Firestorm]

Having done both at both of the stations Rory is speaking about, I was always puzzled as to why the LFB didn't sack off the 90mm hose off the HLU and replace it with HVP hose. The HLU was far superior to the double hose box in both deployment, capacity and the make up, but had the obvious limits with 90mm delivery hose as mentioned here. When I questioned this with the BM tac advisors, they looked at me like I was talking another language, mind you, they were also hell bent on the slowest deployments of HVP known to man.

[Mess6311]

On 18/05/2020 at 16:25, Rory-495 said:

Is that the same as your pump inlet? Would make sense in terms of a water relay to go straight into the eye of the pump instead of into the tank-pump-deliveries as we do in LFB

We dont go straight into the pump eye. HLL has set of kit for Base pump/intermediate pump/ fireground pump. The base pack has 70mm short lengths into a collector to 100mm plus a gate valve (large 100mm trinity). Intermediate has divider and collector with a short 100mm straight through but allows the intermediate pump to take a feed at 4x70mm to the boost pressure at 4x70mm into a collector back into the main supply. fireground then terminates in 4x70mm to the fireground pump. Next time we have it set up i will take a photo, its more simple than it sounds.

[Rory-495]

That... actually makes sense! I think. But a photo would be 1000x times better next time you get it all set up.

Thanks for the explanation!

[StephenKP]

Roger Mardon has a page on the HVP's that were delivered as part of the New Dimension project and has info on the capacities, equipment etc. here http://www.romar.org.uk/page131.html

[Carl]

Its fantastic quoting and linking to all these enthusiast pages, however, lots of information on that page is factually incorrect and it doesn't look like it's been updated since the page was created. 🤷‍♂️

[Carl]

We have both High Volume Pumps and Hose Layers and our default is still the Hose Layer. However, now I am on the FDS and have a little more influence on the fireground than previously, unless I was actually part of the makeup, I am slowly increasing peoples confidence in the use of HVP. It’s been used more internally in the last 18 months than it has in the previous 5 years, so I am making some headway. 

Most of you know the advantages such as the need for less pumps, it can be self-sufficient once deployed, its quicker to get to work, and so the list goes on. For me, the fundamental thing is its use, it supplies a high volume of water, something you will need if you are going to put the fire out. My issue with hose layers is that they are usually 90mm or 100mm, so in essence, 20mm or 30mm bigger in diameter than standard 70mm hose. The HVP hose will double the size of the hose and then some, why would you not want a bigger diameter hose that can send more water to the job, you need it if you want to put the fire out. Another big issue, is that a standard fire engine can't pump from more than a 10m lift anyway, 10m if you are lucky. The HVP will pump from 60m, 80m at 5 other locations around the UK, so dropping it off a pier or bridge is achievable. I know, I have done it and got the photo to prove it. 

The HVP can also run for a good distance too. The longest single line that was run was over 8K in Hamsterley Forest back in 2014. Granted, we used intermediate pumps but we also ran it from start to finish over 350m head. Those on HVP stations will also be aware that there is a black bin fixed in the locker which more than likely has your strops and shackles in there. The origin of the box is for your second impeller. HVPs came with a high flow and a high pressure impeller. Only the welsh brigades have the high pressure impellers fitted. 

If the HVP is deployed correctly it can stay in situ for as long as you want and only needs fuelling every 5 hours, this saves loads of resources but has its limitations of crew rotation on longer jobs.

One final thing that people tend not to understand with HVPs is that you can supply via a pressure fed supply, basically creating a 150mm main over land and putting it where you want, but remember, the HVP will supply you with a flow of water, not pressure. This is another area that people do not understand. If you want pressure, your conventional pumps will have to impart the energy into it and thus the pressure.

This biggest disadvantage with the HVP is that when you run 150mm hose across the roads, you effectively shut them. Running over it is not an issue unless your in a truck. You will soon know when that happened as you glance down the road and see a lamp post coming from your hose.  

For the benefit of our newer members, I was seconded to the Fire Service College in Moreton for 2 years working for the National Resilience Assurance Team (NRAT) as the national HVP Capability Officer, so lived and breathed it for 2 years. Sad I know, but if you have spent time at Moreton, you will know why I enjoyed it. 🍺

Any questions, please feel free to ask

PS, I have attached the Flow Calculator we use to work out what distances you can pump over. Have play with the figures in red which you can change and see the distance. Just by making the lines 2, you will increase the distance and flow. (Inverse Square Law) for those who remember. 

Hytrans Performance Calculator.xls

[Becile]

Ok- you can keep your wages

[Rory-495]

Well... answered my questions and then some! You may as well close this topic with your mike drop of a response!

But honestly, many thanks for a really useful reply

[Carl]

Thats what we are all here for

[Keith]

22 hours ago, Carl said:

The HVP will pump from 60m, 80m at 5 other locations around the UK, so dropping it off a pier or bridge is achievable. I know, I have done it and got the photo to prove it. 

Are there any bonus points available if you can name the location in the photo?

[Carl]

I can name it, and I know you can, but could anyone else ?