Thread: Drop Tank Ops.

  1. #1
    jab1415
    Firehouse.com Guest

    Post Drop Tank Ops.

    If I wanted to do a double drop tank operation which I have seen done in magazines, how do you get water from the drop tank that the tanker is dumping into to the drop tank that is being drafted out of? I hope that makes a little sense. I've heard that you use a peice of hard suction hose with one end in one tank and one end in the other and put a booster hose in the end of the stationary tank forcing water through the hard suction. This I'm told, creates a venturi effect and from that, you are able to pull from one tank to the other. Anyone with experience on this subject?

  2. #2
    Corvin
    Firehouse.com Guest

    Post

    A jet syphon is just a small, often homemade device that will assist you with the process you mentioned. For example, you might take a 6" male thread from a hard sleeve and weld a 1 1/2" female in the center. (leave the space between the two fittings open, just weld some supports to hold the 1 1/2)

    Now hook an 1 1/2 to the the 1 1/2" fitting and a 6" hard sleeve to the 6" fitting. Lower the fitting/hose connection into the full tank and pump into the 1 1/2". Water will 'syphon' out, using the venturi effect you mentioned into the empty tank.

    A number of other depts will interconnect tanks at the base. That practice is not used near me, so I'm not completely familiar with it.

    Let me know if you need a fax picture of a syphon.

    Chris

  3. #3
    Lewiston2Capt
    Firehouse.com Guest

    Post

    They also make a bottom strainer for drop tank drafting with a 1 3/4 fitting on the opposite side of the strainer head from the hard suction fitting. The 1 3/4 reduces down to a 1/2 - 3/4 inch jet and can be used for the same thing. I have heard it called a jet siphon.

  4. #4
    N2DFire
    Firehouse.com Guest

    Cool

    Fol-da-tank makes a connector & bar clamp to join the 10" drain chutes on their tanks together. http://www.foldatank.com/holder.html

    This is something I am looking into for my department.

    Also this is something that LHS "promotes" (for lack of a better term) on both Fallon & Rattle Snakes' web sites.

    Take Care - Stay Safe
    Stephen
    FF/Paramedic

  5. #5
    J Almon
    Firehouse.com Guest

    Post

    One thing to think about if you are in the situation where your flow almost equals the tanked-in amount...
    If you couple the tanks, the levels in both tanks will drop to the same level since the atmospheric pressure is the same on both surfaces. Depending on the situation, it could leave a good amount of water that is unusable due to it being below the strainer.
    On the other hand, if you use a jet siphon, a fraction of your pumper capacity is required to move the water through the transfer line. It is less than 10 percent for a 1,250 GPM pump, but it is more for a 750 GPM. If this is a problem, a portable pump could be used.

  6. #6
    Engine69
    Firehouse.com Guest

    Post

    EXACTLY what I was going to point out. Also, this arrangement permits a maximum of two fold-a-tanks. If you want a third tank, you still need a siphon device. If you are using siphons to begin with, you could have multiple fold-a-tanks in use serving the main drafting fold-a-tank. Siphons are pretty much the standard here, and we seldon have problems with rural water supply.

    Originally posted by J Almon:
    One thing to think about if you are in the situation where your flow almost equals the tanked-in amount...
    If you couple the tanks, the levels in both tanks will drop to the same level since the atmospheric pressure is the same on both surfaces. Depending on the situation, it could leave a good amount of water that is unusable due to it being below the strainer.
    On the other hand, if you use a jet siphon, a fraction of your pumper capacity is required to move the water through the transfer line. It is less than 10 percent for a 1,250 GPM pump, but it is more for a 750 GPM. If this is a problem, a portable pump could be used.

  7. #7
    Daron
    Firehouse.com Guest

    Post

    This may be what you guys are already talking about with a siphon but I never saw it really explained. What I've seen done in an area where I used to fight fire before moving here is 3 5" pieces of PVC pipe with 2 90 degree elbows in between them to form a u shape. We would take this and completely submerge it in 1 tanks making sure the pipe is completely flooded. Then attaching 2 end caps so the water would stay in it and lift it up and over into the 2nd tank and flip it over so one end goes into the 2nd tank and the first end is still in the 1st tank. With both end submerged remove the end caps. This pipe is now joining the 2 tanks and as the level drops in the tank you are drafting out of the 2 tanks will equalize. The pipe would need to be cut to closely match the depth of the tanks and to allow a little room to work with but not so much as to make to bulky.

    [This message has been edited by Daron (edited 05-11-2001).]

  8. #8
    LHS*
    Firehouse.com Guest

    Post

    see www.isoslayer.com for photos of tanks connected together.

  9. #9
    N2DFire
    Firehouse.com Guest

    Cool

    O.K. - before I even start this reply I want to state up front that all this is coming purely from research NOT actual experience w/ linked drop tanks. I still maintain my philosophy that what works for one might not work for another - so do your own research (which your doing) and decide what works best for you.

    That being said . . .

    J Almon - you present a very good point - however the use of a low level or floating strainer vs. the old Barrel type will go a long way to overcoming this problem.

    Engine69 - you also make a good point. You can only link two tanks IF they each only have 1 drain chute. If you are in the situation where you already have good (new) tanks then a siphon would be a better choice for 3 or more tanks. However if you are starting from scratch or have old tanks, then new tanks can be ordered with a drain chute on each side, making the number of tanks you can connect almost endless (within reason).

    If you check out LHS website you will see (I think) 10 drop tanks linked in such a fashion.

    Now - before anyone gets ruffeled feathers, I'm not saying this system is better or worse than other systems, I just wanted to "level the playing field" so to speak by painting a clearer picture of tank linking.

    As I have said before, this is something I am investigating for my own department and I readily welcome your input on Pros as well as Cons to this (or any other) system.

    Take Care - Stay Safe
    Stephen
    FF/Paramedic

  10. #10
    Engine69
    Firehouse.com Guest

    Post

    It was not my intention to "bad mouth" a particular system. If linking port-a-tanks at the drain shutes works for you, I am all for it. As with anything else we do, you need to practice the procedure and be proficient at it. If you have the "big one" and your mutual aid departments use the same concepts, you're good to go.

    I do like the idea of having two drain shutes on your port-a-tanks. I can't tell you how many times in the middle of the night and in the heat of battle that a port-a-tank ends up with the drain on the uphill side. The last thing I want to do after a good size fire, is to fight with the remaining water in the dump tank. For that reason alone, I would agree with Stephen to order new port-a-tanks with two drains... that way you have the option available to connect them together at least, even if you don't currently do so.


  11. #11
    N2DFire
    Firehouse.com Guest

    Post

    Hey Engine69,

    I don't think you were bad mouthing a system, and I didn't mean to come across like that. If I did then I apologise. Like I said before - you & J Almon made very good and very valad points - I just wanted to give possible solutions to them.

    As a side note you make another good point about mutual aid using the same system.
    While researching this I have heard (not seen nor tried - yet) that you can take 2 drain chutes and link the tanks by "inverting" one chute and slipping the other inside it - then rolling a cuff in it to hold them to gether. That might be a possible solution to the Mutual Aid problem. The only down side I see is that you loose the ability to clamp that chute closed and disconnect the tanks(i.e tank failure or simple break down & release of M/A equipment). I'll belive this one when I see it.

    Once again - I hope I have not offended nor steped on toes.

    Take Care - Stay Safe
    Stephen
    FF/Paramedic

  12. #12
    LHS*
    Firehouse.com Guest

    Post

    //The only down side I see is that you loose the ability to clamp that chute closed and disconnect the tanks(i.e tank failure or simple break down & release of M/A equipment).

    Simply use the $40 dollar bar clamp that comes with the connector clamps and shut off the drain. Easy and simple, a conventional hose camp works as well.

    //possible solution to the Mutual Aid problem.

    A second, 3rd or 4th suction line, ie. ideally 3" or 5" or whatever, can be used to connect anyone directly from their dump tank to the pump and skip the entire tank transfer process. Certainly it is a universal mutual aid solution.

    Any tank can have chutes retrofitted after you own them. Simply ask the supplier how, I've done it a few times.


  13. #13
    OLE
    Firehouse.com Guest

    Post

    I would have to agree with JAB, we have a water jet system that we can draft from 6 other drop tanks and it works great!! We only had to use it once at a grain bin fire at an elevator. And no, it really doesn't take a lot of water or pressure to move from 1 tank to another. If you're using more than 3 drop tanks at a time, you'll probably need mutual aid anyway.

  14. #14
    Chiefkeo
    Firehouse.com Guest

    Post

    I spend many of my weekends as a part of a team that supervises major structure burns for the purpose of water shuttle training. We use the jet siphon tubes and have occasionaly had access to chute connectors. The jet siphons we use are 5-6" PVC pipe with 1 1/2" connectors fed to a 3/4" copper pipe into the center of the tube. I prefer the jet siphons because of the ease I see in growing the system as needed. We encourage the storage of the drain chute on the interior of the drop tank because when it is located on the outside sagging often reduces the amount of water the tank will hold before over flowing. Once a tank is on the ground and filled it is impossible, at least with the connectors I've seen to connect to the drop tank in use to expand the system. I have had as many as 15 drop tanks working at once. With the jet siphons I can better gauge my available reserve at any given time. I can also concentrate the supply to the pumpers doing the majority of the work at any given time. If all the tanks were connected with chute connectors wouldn't the tank to tank transfer be too slow to maintain pumping levels during times when you are pumping 1000-1500 GPM from a drop tank. There are times when I will have 4 jet siphons running into one single supply tank. Just so I don't get in too much trouble here I would say that chute connectors will most likely work well enough in a system set up ahead of time but they seem to have their limitations from what I have seen. With the jet siphons I can adjust the system any time I need by relocating or changing direction of flow. I should mention that I have had as many as 4 pumpers working together from this supply system. If there is something I'm missing about the chute connectors please pass it on. Always willin to pick up new ideas. Thanks

    ------------------
    I shall fear no evil, for I am a Firefighter

  15. #15
    LHS*
    Firehouse.com Guest

    Post

    You're from Iowa huh?

    Why are rural fire services so bad in that state???

    Top Ten States with the Worst Average ISO Grade
    1. North Dakota 8.6
    6. Arkansas 8.02
    2. South Dakota 8.4
    7. Iowa 7.9
    3. Oklahoma 8.3
    8. Indiana 7.7
    4. Minnesota 8.1
    9. Kansas 7.64
    5. Maine 8.04


    Top Ten States with the Class 9ís by number
    1. Iowa 993
    6. New York 771
    2. Minnisota 940 7. Arkansas 755
    3. Ohio 911 8. Indiana 711
    4. Missouri 843 9. North Carolina 700
    5. Michigan 818 10. Pennslyvaina 667


    Class 9ís by percentage
    Iowa 47.1%

    //I have had as many as 15 drop tanks working at once. With the jet siphons I can better gauge my available reserve at any given time.

    How do you do you control 15 tanks at once?

    I've never had more than 21 - 4000 or 5000 gallon drop tanks coupled end to end at one time and we shuttled in excess of 7000 gpm, so water transfer between tanks was never an issue.

    //If all the tanks were connected with chute connectors wouldn't the tank to tank transfer be too slow to maintain pumping levels during times when you are pumping 1000-1500 GPM from a drop tank.

    It has never been an issue here. A 10 inch drain is awfully effective at maintaining water level.

    //There are times when I will have 4 jet siphons running into one single supply tank.

    That's 472 to 600 gpm worth of pump capacity in use isn't it?

    //Just so I don't get in too much trouble here I would say that chute connectors will most likely work well enough in a system set up ahead of time but they seem to have their limitations from what I have seen.

    Well, we can jet our 10 inch drains or use gravity, if going one direction we hit a flow restriction at 2500 gpm without a jet, or 5000 gpm when we operate properly going both directions, jets just keep the tanks full and we use a floating pump for that.

    //With the jet siphons I can adjust the system any time I need by relocating or changing direction of flow.

    We don't worry about any of that stuff all the tanks stay the same.

    // I should mention that I have had as many as 4 pumpers working together from this supply system.

    We've supplied three 2300 gpm pumps simultaneously.

    // If there is something I'm missing about the chute connectors please pass it on. Always willin to pick up new ideas. Thanks

    Yeah, hook them up and forget about them, no controlling flow, no pump capacity wasted, and get an ISO Class 3.


  16. #16
    Chiefkeo
    Firehouse.com Guest

    Post

    Originally posted by LHS*:
    You're from Iowa huh?

    Why are rural fire services so bad in that state???

    Well LHS I've heard others refer to your posts as negative and attack oriented but I'm gonna give you the beneifit of the doubt here. So if you are truely asking that as a question and not as a smartass comment then here.

    Could it be, let me see, Average polulation of communities, career vs volunteer dept. ratio, average income, age of population, politics (we'll see what ratio of the fire grants go to the states you named), the fact that many insurance companies in Iowa according to insurance agenst treat a class3 or 4 the same as a class 7 (which we are), value of taxable non land property ( most of the value here is in the land, not much fire protection needed there). I'm sure there are other reasons but you most likely know that since you seem to have access to a great deal of data.

    How do you do you control 15 tanks at once?

    Easy. We use a manifold system. All we have to do is flip a lever and move the water whenever and whereever we need. Also the manifold system as with the jet sipons can easily be expanded anytime during and incident as well as broken down to release mutual aid units. You neglected to explain to me how you do that with your chute system.


    It has never been an issue here. A 10 inch drain is awfully effective at maintaining water level.

    Thank you. I was looking for some useful information with that question just as the original poster was looking for VARIOUS ideas.

    That's 472 to 600 gpm worth of pump capacity in use isn't it?

    Don't you think it would be hard to pump 600 GPM through 4 - 3/4" pipes?

    Well, we can jet our 10 inch drains or use gravity, if going one direction we hit a flow restriction at 2500 gpm without a jet, or 5000 gpm when we operate properly going both directions, jets just keep the tanks full and we use a floating pump for that.

    Ok so now we've added a floating pump and jets?? So why are we using the connectors? And if I understand correctly you are jetting the drian chutes through the chute connectors? I'm still missing how you add in more tanks if needed


    We don't worry about any of that stuff all the tanks stay the same.

    So when your water level gets low all your tanks are low. With Jets and can drop water directly in front of the pumper and mot worry about it flowing into all those tanks beside it. Therefore I can maintain a higher level where I need it. Understand?

    We've supplied three 2300 gpm pumps simultaneously.

    Great next time I'll hook up 5 1500 GPM pumpers just so I can be bigger than you. Give me a break this isn't about numbers its about ideas and concepts.

    Yeah, hook them up and forget about them, no controlling flow, no pump capacity wasted, and get an ISO Class 3.

    Great if it works for you I'm happy for you. I'm not going to trash your choice. Maybe try providing the facts and acceping that there are other ideas out there LHS. You know even you can't be right all the time.

    To anyone else sorry if I got negative on this one. Just kinda hate kow it alls. This is the system we use. We like it. Take a look at all the choices and determine which works best for you.
    ------------------
    I shall fear no evil, for I am a Firefighter

    [This message has been edited by Chiefkeo (edited 05-20-2001).]

  17. #17
    LHS*
    Firehouse.com Guest

    Post

    Gee I provided lots of other options to this topic.

    Here's another Rattlesnake's:
    One department goal was the ability to get a draft with just one firefighter in 15 seconds. A second goal was the ability to get a draft from a drop tank while the unit attacked a fire off tank water without losing prime and/or add a second, third or fourth suction line. A third goal was the elimination of the primer in most drafting operations. The final goal was to eliminate transfer devices between drop tanks by using multiple hard suction lines, one to each drop tank.

    In order to accomplish the above, both sides of the unit have a 24 foot squirrel tail suction hose. One hose is 5 inch and the other is 3 inch. One end is stored connected to a gated pump suction with a preconnected low lift strainer with a foot valve built in. The engineer simply pulls the velcro mounted hose off the rig and drops the strainer into the cistern or drop tank. Then he partially opens the side intake valve and the hose back fills and self primes against the foot valve. The engineer fully opens the side suction valve and the draft is accomplished. Three low lift and one floating strainers are carried to allow maximum flexibility. There are five 14 foot spare lengths of hard suction, Three 3 inch (one with another low level strainer attached) and two pieces of 5 inch (one with a floating strainer attached). All connections are cam lok couplings are carried to allow extending or building additional suction lines.

    There is no faster or a more problem free coupling for drafting or fill operations than a cam lok coupling. One end is male the other female. Simply push one fitting into another and pull two handles and the coupling is attached. Reverse the process to disconnect. There are no threads to damage or cross thread. The days of air leaks and hammering couplings with a rubber mallet are over. When the lines are connected it allows for a 74 foot 3 inch hard suction or 54 foot 5 inch line. The 3 inch and 5 inch suction can be connected end to end up to 128 feet. All suction fittings and strainers are color coded to the truck that carries them and laser etched Rattlesnake FPD. Everything on Engine 1 is color coded orange, from drop tanks to strainers and fittings to couplings. Engine 2 green and Engine 3 is blue. The color coding insures equipment gets back to there respective apparatus. The 5 inch squirrel tails primary use is to fill the rig at draft. The quick disconnect fittings allow the hard suction to be disconnected from the pump suction and left in place for the next rig to use.

    The foot valve will hold the prime. The lightweight easy to move 3 inch hose is used to draft from port-a-tanks. A single 3 inch suction can bring in 400 gpm at draft, enough to supply a pair of attack lines. If more than one drop tank is in use a second 3 inch line can be put into service instantly. The operator can balance drop tank volume by simply gating the side suctions. For high fire flows a 5 inch suction can always be used, it is also the line pulled for a third or fourth drop tank operation. A primer selector valve allows adding a second, third or fourth hard suction while already drafting or pumping off tank water without losing the prime.

    pictures http://www.geocities.com/Baja/Trails/7873/index4.html


    Connector clamps and bar clamps are located on each end of the 3500 gallon drop tanks to allow tanks to be connected together. All drop tanks are color coded to the rig they came off of, Blue, Red, green etc. Upto 5 drop tanks are used at one time plus MA units.


    [This message has been edited by LHS* (edited 05-20-2001).]

  18. #18
    Chiefkeo
    Firehouse.com Guest

    Post

    Thanks for the informative and cooperative post LHS. Your system as you now descripe it does sound very functional and and flexible. I would only wonder as to the price tag for all those fittings and valves. I know we hate to think that price shoudl determine if we get the best set up or not but for many it is a fact of life. I know it would be tough to break down each item but could you maybe give us an idea of what the whole package costs? Thanks

    ------------------
    I shall fear no evil, for I am a Firefighter

  19. #19
    LHS*
    Firehouse.com Guest

    Post

    Cam Locks cost 60% less than threaded fittings, and 25% less than storz, clear suction hose is half the price of hard rubber. Not having a pump panel of the fire truck saved the money to buy things that really fight fire. Overall cost @$3500.

    End result a Class 4 district wide and a few hundred bucks per homeowner a year.

  20. #20
    Chiefkeo
    Firehouse.com Guest

    Post

    Thanks LHS. Your post also made me understand why some districts find it easier to justify the cost of a lower ISO rating than others. My house would be considered one of the better homes in our community and I don't even pay a few hundred bucks a year for my insurance. Guess that high dollar housing helps alot doesn't it?

    ------------------
    I shall fear no evil, for I am a Firefighter

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