Thread: Front bumper drafting...........
04-05-2001, 02:27 AM #1steveoFirehouse.com Guest
Front bumper drafting...........
I am training officer of a volunteer dept with 50 members. Was told that the front bumper intake on a pierce lance pumper/ tanker in not engineered to be used during drafting operations. Is this true? I have done this on this truck before and know that it can be done. Question is does pierce so specifically not to. Questions two- can you draft with the clear hard suction light hose? Again told that it is not to be used for drafting. Again I also have done this in the past. Is there anyhting that says you should not draft with this hose. Thanks for the help -steve
04-05-2001, 09:27 AM #2Gregg GeskeFirehouse.com Guest
I believe the front intake can be used for drafting operations, but you might not want to use it if large flows are required. Because the intake piping has at least (2) 90 degree angles and (4) 45 degree angles and has to neck down in size to get around the wheel well, you are limiting the cababilites of the pump by using the front intake. You may not be able to do an annual pump test or draft capacity from the front because of the friction losses encountered from the route the plumbing has to go to get to the front. By doing some testing you can figure out what GPM limits your front intake has. Clear hard intake hose was designed for suction. You can check out NFPA 1961(Standard on Fire Hose) 2-6 to see if your hose meets the standard, most likely it does.
04-05-2001, 12:02 PM #3RhinofireFirehouse.com Guest
I have to agree with the previous post. The front bumper intake will work but you will probably not get the same flows as your side intakes. Though these flows are less they are usually sufficient for most operations. I advocate trying and find out what you can flow from your front suction. The one thing the front or rear intake allows you to do is set your folding tanks inline with the apparatus to block less of the roadway. As far as I know the only thing you should not do with the clear suction hose is to hook a hydrant with it. The stuff we have is not rated for a pressurized water source. It was attempted in my department and the couplings separated from the hose. No major disaster just had to reattach them.
04-05-2001, 12:24 PM #4Bob SnyderFirehouse.com Guest
On the first point, Gregg has hit on the issue. The other thing to consider here, of course, is "how was the truck spec'ed?" We specifically spec'ed our engine and our squirt to have front suctions with straight shots to the pump. One is a CF Mack, the other a Pierce Arrow, and they both have full flow ratings from the front. I'm not saying that your rigs are like this, just that, for future reference, you can spec this.
Second, we use lightweiht hard suction hose exclusively, and, as Gregg said, it's meant only for suction. Put a section of our lightweight suction on a hydrant, and you'll blow the hose right out of the couplings (saw somebody do this).
04-05-2001, 03:28 PM #5RJEFirehouse.com Guest
I never did it with your model of truck, but...
With a Seagrave custom, the front suction had several bends that limited flow in draft, as in the other posts. We always used the side intakes (direct into pump body) for draft operations.
On the other hand, we kept a 25' piece of 5" soft hose on the front bumper. This was for hydrant hookups. The front intake was gated, so we could set up on the booster tank, then safely connect a supply line w/o risk of losing prime. With a pressurised supply, the extra loss was hardly noticable. And we never had to worry about using the "wrong" hose for a hookup. Draft was hard sleeve (but we didn't have "clear") and hydrant was the soft sleeve.
04-05-2001, 06:09 PM #6HFD_CLangerFirehouse.com Guest
Although most of these points have already been mentioned, I will add/emphasize the following:
As far as the front suction goes, I have never heard of not being able to draft with one, but you may want to double check with Pierce to make sure there is no warrantee issue there. As far as flows go, you may want to (as mentioned earlier) spec any future rigs so they will give you full flow.
Regarding the clear hard suctions, are you sure that you weren't told that they should ONLY be used for drafting? Most of the older heavy-weight hard suction could be used for drafting and hydrant connections; most of the newer lightweight suction hose may only be used for drafting. Again, check the markings. Most likely it will read something like "CAUTION - For vacuum use only - Do not use on hydrant or relay."
Hope this helps.
04-05-2001, 10:01 PM #7steveoFirehouse.com Guest
Thanks for all the information. I know that the intake has a lot of bends which would definately cut down on flow. I will talk to Pierce and straighten out the older guys. Thanks steve
04-05-2001, 11:04 PM #8Ten8_Ten19Firehouse.com Guest
Something doesn't make sense to me. We've been working on new truck specs and we looked at conventional vs custom. We knew we wanted a front suction and one rep said to beware the conventionals because the plumbing has to take so many twists and turns getting to the pump you're not going to get full flow. Okay, fine. Then we look at customs and nearly all of them use a 90 up through the bumper and another 90 above that. Isn't this defeating the purpose? Why don't they just leave it with a straight shot through the bumper?
04-07-2001, 12:46 PM #9ArmyTruckCompanyFirehouse.com Guest
The majority of manufacturers can not produce a unit with a front suction that is straight from the bumper to the pump- the reason?? There are several, actually- the steer axle, the engine, the transmission, and the transfer case. These impede a straight shot all the way through. The only manufacturers that I know of that were able to do it efficiently were Mack, when the CF was still in production, and Ward LaFrance, when they built the Ambassador chassis. But even the greats had to have some bends.
As for the other posts, I agree wholeheartedly!! We have a 1978 Hahn 1250gpm with a front intake. On a good day, with 2 lengths of hard sleeve and a 10' or less lift, the most we can do is 900gpm. However, move to the side intakes, same scenario- 2 lengths, 10' or less lift....I have moved 1400gpm through her!! The only reason I couldn't move any more is because I ran out of throttle and discharges!!!
As for the clear lightweight sleeves, we use these in conjunction with a Kocheck floating strainer, and it is a great combination!!! We have never had any problems!!
"Loyalty above all else, except honor."
04-07-2001, 01:07 PM #10LHS*Firehouse.com Guest
Take your rig out and find out for yourself how many gpm you can draft out the front suction using your hard suction and plumbing. Then let us know.
04-10-2001, 03:28 PM #11GCFirefighterFirehouse.com Guest
In my department we have a front mounted suction on a 1991 Pierce Dash and we have had no problems at all drafting with this setup.
Grove City Fire Dept.
04-13-2001, 03:04 PM #12res7cueFirehouse.com Guest
We've found that the front intake was running between 900-920 gpm.
Like ArmyTruckCo stated, too many components on the chassis to allow for a straight run of piping.
We still use our front intake 90%+ for drafting due to function.
This is on a 1996 Pierce Dash, 1250gpm Waterous. Our '88 Hahn. 1000gpm Hale is a little better, about 950gpm, I believe during the last test.
The side instake has always been the best choice for drafting, but just not functional most times.
[This message has been edited by res7cue (edited 04-13-2001).]
05-05-2001, 09:29 AM #13James ReiderFirehouse.com Guest
We have a front suction intake on our "95" Pierce Saber. With the 90 degree elbrows and the 45 degree elbrows. We can draft only 800 to 900 GPM. This engine is a 1500 GPM.unit, while laying out specs for a new engine we had talk with alot of other departments and they suggested an rear suction. We than speced a rear suction with full pump capcity from draft. Pierce couldn't give us any data as to the intake gallons of thier suction. Their pump engineer is on our department and stated that they have not tested the intake. They figure the flow is between 900 to 1000 GPM. American La France did show that they can flow full pump capacity from draft by going straight into the pump from the rear. You will lose storage space going straight in the rear. By going in on the right side rear they can give us 1290 GPM. With little storage space lost.
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)