Thanks for the info and apologies for the misspelling (hangArs). This is not something I do on a regular basis. (I think I've only done 3 hangars since the 80's).
This reminds me of my first, Dyess Air Force base in Abilene, TX back in the 80s sometime when the B1 Bomber first came out, we did a hanger for it. Very souped up foam systems(deluge), lots of monitors etc. Impressive during the tests, system refilled & left in service. About a month later we get a call that says they need more foam and their systems re-set up. Seems a private on guard duty had "accidently" pulled the manual trip switch....The B1B in the hanger was opened up and needless to say had a lot of soap suds on the electronics. Talk about a mess ☺. If I recall at that time the pop-up type sprinklers were not available and maybe were invented because of this!! Good times back then. Anyway thanks to all for the help. Don Lowry, CET, Texas RME -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Bob Holland Sent: Tuesday, January 06, 2015 12:28 PM To: [email protected] Subject: RE: Foam & HangArs A few years ago while at URS I was part of a team doing hangars for Executive Jet, Nationwide, US Air, Tenn. Nat'l Guard, Proctor and Gamble and others, a bunch of them. When we started NFPA 409 was only mentioned in a list of related applicable codes. IBC 412. 4 through .6 did not exist. IBC 412.4.6 now lists what cannot happen in a hangar without foam. I strongly advised getting a copy of IBC 412 with the Commentary. It is based on 409 but affords greater general clarity via the Commentary. Details remain in 409. I've not seen a mention of draft curtains in the dialogue below. As I recall these establish zones based upon allowable fire areas per construction type and a 75' circle 'sets off' the zones. Worst case is an interior zone (not left or right perimeter) where the 75' causes three zones to activate. Water calculations were based on this. There were several ways to deliver foam, overhead gets into aircraft and cannons can be obstructed or otherwise problematic. The preferred method after it was developed with the air force was the 'pop-up' sprinklers in the drainage trench. It took a couple of years to garner approval. Sneaky aircraft prefer this method. This system covers the floor where most fuel fires originate and drains away quickly if the floor is properly sloped and creates less mess. A lot less. There was a video in circulation many years ago of an overly concentrated AFFF - water mix filling a hangar. Ellsworth AFB as I recall. Its real. For the more advanced and fool proof systems IR/FR detectors were used and abort buttons were located in numerous places. Be aware of the pump redundancy requirement. Effluent may be an issue. We drained foam areas only through a weir with automatic sluice gates, normally open to storm through an OWS, when activated the OWS was by passed and the mess went to a rubber lined pond or a lined concrete tank for containment and gradual release to the sanitary sewer subsequent to communication with the local sewer district. AFFF kills good bugs in a treatment plant. At one point sharing the effluent pond came up and with the help of actuaries determining the likelihood of two hangars on the same airfield in the same 72 hour period was one to the negative eleventh. Testing involves a dump unless otherwise accepted without it by the AHJ. Usually they've not seen such an event so plan on it. If its overhead, cover the walls with plastic well secured. ROBERT HOLLAND Jr. AIA, CDT, LEED AP, PMP ARCHITECTS / ENGINEERS / INTERIOR DESIGNERS 7400 West Campus Rd. Suite 150 New Albany, OH 43054 www.shremshock.com t 614 545 4550 x 286 f 614 545 4555 [email protected] Please consider the environment before printing this e-mail. -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Don Lowry Sent: Tuesday, January 06, 2015 10:57 AM To: [email protected] Subject: RE: Foam & Hangers Chris, I believe this has already been hashed out with the owner / city but I have pointed out the IBC quote in case they missed it and will await a response, before I move forward in the design/pricing. Thanks for all your help. Don -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Cahill, Christopher Sent: Tuesday, January 06, 2015 9:23 AM To: [email protected] Subject: RE: Foam & Hangers If you meet the letter of the code the City doesn't get a vote. AHJ don't have to approve exception unless there is something to the effect of 'exception...where approved by the building official....'. In this case the exception doesn't say where approved. Are you storing only transient aircraft in a group II hangar? Are there separate repair facilities? If that is the case you don't need foam no matter what the AHJ wants. Now if you are storing aircraft based there (not transient) for example you don't get the exception and the power position shifts to the AHJ. There really aren't a lot of these kinds of hangars so you probably don't get the exception. I was just offering another way out. I've had a couple cities favorably rule based aircraft and light maintenance still met the exception thus no foam. But that creative interpretation of the meaning and intent is up to the AHJ. Chris Cahill, PE* Associate Fire Protection Engineer Burns & McDonnell Phone: 952.656.3652 Fax: 952.229.2923 [email protected] www.burnsmcd.com *Registered in: MN Proud to be #14 on FORTUNE's 2014 List of 100 Best Companies to Work For -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Don Lowry Sent: Tuesday, January 06, 2015 8:51 AM To: [email protected] Subject: RE: Foam & Hangers Thanks to all for the response, I was just verifying I was reading that correctly about the entire hanger being calced at once. Chris, Thanks for that reference, I will point that out to the project. Awhile back the builder told me they had found an exception in the IBC where it didn't need foam but the city was not accepting that exception. I will ask if this is the case? Thanks, Don Lowry -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Cahill, Christopher Sent: Monday, January 05, 2015 5:43 PM To: [email protected] Subject: RE: Foam & Hangers Seems to me it reads all 16,900 sq.ft. which is not typical with multiple systems in our world. But do you even need foam? See IBC: [F] 412.4.6 Fire suppression. Aircraft hangars shall be provided with a fire suppression system designed in accordance with NFPA 409, based upon the classification for the hangar given in Table 412.4.6. Exception: Where a fixed base operator has separate repair facilities on site, Group II hangars operated by a fixed base operator used for storage of transient aircraft only shall have a fire suppression system, but the system is exempt from foam requirements. Chris Cahill, PE* Associate Fire Protection Engineer Burns & McDonnell Phone: 952.656.3652 Fax: 952.229.2923 [email protected] www.burnsmcd.com *Registered in: MN Proud to be #14 on FORTUNE's 2014 List of 100 Best Companies to Work For -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Don Lowry Sent: Monday, January 05, 2015 4:06 PM To: [email protected] Subject: Foam & Hangers Ref 2004 NFPA-409 Situation: Group II hanger Option # 4, Closed-Head Foam-Water Sprinkler System 16,900 Sq Ft total hanger size So, per 7.6.4 we'll need 2 systems (8K and 8900) respectively so as not to exceed 15k per system. 7.6.2 states minimum design density .16 gpm/sqft over entire storage and service area. Question; Based on 7.6.2 I've got to calc both systems at the same time, for the entire hanger area. (lots of water). Am I interpreting this correctly or does this mean calc the entire area of each systems individual floor area? Thanks in advance, Don Lowry _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
