View Full Version : LDH Relay for 1 mile
billy
04-18-2002, 07:40 PM
Anybody ever pumped a relay of LDH for 1+ mile? Problems, tips, innovations???
Dalmatian90
04-18-2002, 09:17 PM
8500' with 200' elevation increase.
Got the officers & truck drivers together at the start and went over the plan so everyone was on the same sheet of music, such as
-- What intake pressures we wanted
-- What discharge pressures we wanted
-- Who would lay what part
-- Who would go where in the final relay
Then started laying.
3 departments contributed 4500', we finished off with 4000' of our 5000' and the two relay pumpers positioned themselves appropriately while we were laying and setting up at the water hole.
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On some long lays (3000' +) were we want high flows, we'll put the Humat 4 way hydrant valve in the middle of the lay. Allows us to charge the line and then a mutual aid pumper can insert itself to boost the flow without interrupting it.
quintladder
04-19-2002, 11:43 AM
Sure, it takes 2.5 minutes with two rigs to get the hose down and water flowing. 1100 gpm at 220 psi EP. Took two guys. One guy with one rig took 7 minutes and flowed 880 out of a monitor. 5200 feet of 6" took the same time and flowed 80% more. In all cases one pumper at the water source and one at the end except the 7 minute job which supplied a monitor. The first time we ever did it we just did it with a mutual aid neighbor, no discussion just done.
Tricks, lessons? Always charge the hose line while you are laying it. It greatly reduces the fill time. Have each rig in line back fill their portion of the hose off tank water in multiple rig operations. Avoid all 4 way valves except the big Akron or a LDH by LDH by LDH by LDH Humat. The others all eat too much energy. Use attack LDH. If you have to carry as much hose as possible in a small space use Neidner LDH. You'll get lots of kinks at the hook up ends but carry 1/3 to 1/2 more hose than the rubber stuff in the same space. Practice with one man crews. Odds are if they can do their role from draft or a hydrant so could more guys. Identify all water points on in rig maps. Figure out how you'll get the water In order of highest potential return 1. Multiple hard scution lines, 2. Multiple Turbo Drafts, 3. One hard suction, 4. One Turbo Draft, 5. A dry hydrant, 6. Multiple portable pumps, 7. a portable pump. Properly set your intake relief valves. Lay hose in the gutter, take care of kinks and hose movement before it is charged. Avoid 4 inch and 6 inch hose.
I'm not sure it makes much sense to put rigs in line. For example adding one rig in the middle. Would you really wait for the third rig to get there? Odds are you want water now. Unless it is for just one property where you designate in advance where everyone stops and starts you can really have surprises. Like, not having exactly enough hose to pull the lay off, that rig is out of service that day so you get less hose, smaller hose or smller pump, arrives sooner than expected, or another of the rigs doen't make it.
So what do you get adding a rig in the middle? An extra 300 gpm or 27%. A fourth brings 300 more 18%. So you've double the rigs, working parts, chances of failure to increase the total flow 60%. Laying two lines would be quicker, and flows the same as four rigs in relay.
The most elevation we've taken on was 350 feet on a 24,000 foot lay.
quintladder
04-19-2002, 01:22 PM
2000 feet of 5" on a 100 foot CAFs quint
quintladder
04-19-2002, 01:30 PM
The engine packs 3000 feet that runs with this quint so 1 mile is no big deal. MA can bring 6000 and 8000 foot beds of hose.
quintladder
04-19-2002, 01:36 PM
5
agtcooper
04-22-2002, 09:56 AM
24,000 of supply line? We had a fire a couple of weeks ago where we laid about 2,000 of dual 3" and we thought the world was coming to an end when we had to pick it all up, not to mention cleaning it!!
Hats off to you guys!!!
Rescue101
04-23-2002, 02:13 PM
We use inline relay valves,just have the reel truck cut them in every 1000' or so depending on elevation.Start pumping and as the incoming engines arrive they just hook to the valve turn it on and boost the flow.T.C.
pres41
04-29-2002, 06:15 PM
Dalmatian90
My question is what was the flow in GPM at the end of this 8500' relay, if it was less than 500 gpm, was it worth it? Was the first engine at a draft or on a hydrant? If the 1st engine was at draft I doubt very seriously if it would do its rated capacity. Remember 5lbs every 100' for 1000 gpm in 5" plus 5lbs for every 10' of elevation, you do the math. I used 3 engines at about 2800' apart with a 50lb residual.
Dalmatian90
04-29-2002, 09:13 PM
My question is what was the flow in GPM at the end of this 8500' relay, if it was less than 500 gpm, was it worth it?
There's several answers to that.
First, the flow was 1000gpm.
Second, was it worth it? The fire itself wasn't going anywhere and from a firefighting standpoint wasn't worth a gallon of water -- it was a charcoal kiln that broke open. However State DEP Air Quality got involved and ordered the fire extinguished. After 8 hours of shuttling water without impact, and 2am my department was toned out to assist in the hose lay (it was a 20+ mile response). Hose takes less manpower per gpm and is inherintley safer than tanker shuttles. So given a fire that department was told had to be extinguished rather than allowed a couple days to burn the fuel load down, a hose lay was the best option.
Several hours of master stream worked cooled the kiln enough for an excavator to overhaul it, followed by several hours of wetting down the remains the excavator spread.
Was the first engine at a draft or on a hydrant? If the 1st engine was at draft I doubt very seriously if it would do its rated capacity.
http://www.mortlakefire.org/Mortlake/DrillPics/06279903.gif
With trucks designed to draft, that's not a problem.
Does 1400gpm at draft @ 10' lift using the squirrel tail 30' 6" suction due to limitations in plumbing to the pump (a tradeoff for the convience & extra reach of the front suction). Second 30' 6" length can be connected to a steamer to deliver 1800gpm at draft. That morning we did take the extra couple minutes to connect the second suction just in case, and the lift probably was 8' when we started and a bit more than 10' when we ended six hours later.
(http://www.mortlakefire.org/Mortlake/Apparatus/Engine_190.htm)
(fyi, the pic above Engine 190 had just laid out 2000' of 5" from a farm located on a narrow, winding town road to a drill dump site being setup on a state highway. It went to setup at a hydrant as the tanker fill site for a "pump-off" (no dump tanks) style shuttle that sustained 1000gpm 3 miles (one way) from the fill site.)
Remember 5lbs every 100' for 1000 gpm in 5" plus 5lbs for every 10' of elevation, you do the math.
I will in a minute...
I used 3 engines at about 2800' apart with a 50lb residual.
Why on earth would you waste that much water as a residual pressure? We use 20psi *maybe* at the start, and it's not unusual for us to suck it down to 5psi incoming. We're not pulling out of a hydrant system where you might worry about collapsing pipes here -- hose starts to go suck, you adjust your discharge, open your tank-to-pump or some combination of those.
So we need 85 x 5 = 425psi friction loss and 20 x 5 = 100psi elevation loss. Add in 20psi residual. That's 545psi, divide by three (source pumper & two relays) that's 180psi each.
Supply LDH has a working pressure of 180psi, so we're within specs there.
The Source pumper is easily able to discharge 1000gpm @ 180...indeed, could approach 1500gpm with dual suctions if neccessary.
The Relay pumpers all our 1500gpm. So 1000gpm @ 180psi is a piece of cake for them as well.
tankerpumper
04-29-2002, 09:37 PM
When we pumped our 8500 foot lay with 300 feet of elevation gain, the elevation gain didn't effect the flows at least not the way the book said it would. The city engineer measured all the flows. Using one pumper pumping to another pumper 8500 feet away and the same thing with one pumper pumping a pair of guns, the ISO guy and our engineer got the same readings. 1303 gpm withone rig pumping to another 8500 feet away and the guns flowed 1112 gpm. Another lay without the elevation gain showed similar flows. It did take 8.5 minutes to layout and flow water though.
Twin lines gave us: 2235 and 1912 gpm respectively.
tankerpumper
04-29-2002, 09:40 PM
If we'd put a rig every 2800 feet we'd have flows of:
1600 one line only a 300 gpm gain to 3200 gpm (+1000 gpm) but would need to use more apparauts
Rescue101
04-30-2002, 07:57 AM
Dal,I guess my question is do you have the inline relay valves or do you go engine to engine?We've got three valves and they are the cat's a** when it comes to long lays.Pump a mile at capacity?Childs play and keep the 20# residual to boot.Start the line with what you got and just keep the incoming engines hooking onto the valves.No shutting down,no splicing (except to the valve/engine hookup)just water supply at it's best.If you had enough valves you could pump 5 miles over any elevation,just need to space the valves closer.a real time saver and a effecient tool to boot.T.C.
Dalmatian90
04-30-2002, 12:55 PM
We avoid inline relay valves when we can, use them when we need to.
The preference is to go right into the steamer of the relay pump, avoiding friction loss of the relay valves.
We have four area departments we've drilled with as our designated relay pumpers so that we're all on the same sheet of music as to how the relay is going to be pumped. If we go far outside our area, either we'll send our ET with a 1500gpm pump to relay and/or have a quick conference like the situation above to get everyone together.
If we are doing a long lay *and* we'll want high flows *and* there isn't another Engine due in the next few minutes (we lay at 1000'/minute; setup/prime takes about 90 seconds; charge at 1000'/minute -- a 3000' lay is an 8 minute evolution) the Engine will stop, put the 4-way Humat LDH hydrant valve in the middle, and continue. Another pumper can tie into the Humat as if they were coming into reinforce a hydrant.
Even out to 5000' we can move 750-1000gpm under most conditions without a relay pumper. Inserting a single relay gets us into the 1250 plus a bit range...so it's a balance if the extra time to insert a relay valve is worth the extra GPM. Now I suppose if we had multiple valves to put inline to get us into the 1500+ range even on long lays that would work too.
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Of course speculating on the future, the Mack is due for replacement around 2012 or so. A nice rear mount 3000gpm pumper with a conventional split hosebed (and a system like Angus' Fetch http://www.fireweld.com.sg/FIRE/Fire%20Hose/Duraline7.htm or LiquidTrans' www.liquidtrans.com to pick it up!) with something like 6000' of 6" would pretty much eliminate the need for relay pumpers on all but the longest/highest flow scenarios, since it could deliver 3000gpm 3000' and still get us 1250gpm a mile out.
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