denmark airport water refill project interim report

INTERIM REPORT
DENMARK AIRPORT (WA) IMPROVED WATER BOMBER REFILL PROJECT
March 2016
Fred Moreno, Chris Howden, Denmark Airport Association Inc.
Chris Hoare, FCO, East Denmark Bushfire Brigade
Summary
Aerial fire fighting effectiveness in our area has for years been substantially constrained by inability
to refill DPAW Air Tractor water bombers quickly. Fill times of 5-8 minutes (highly variable) and
nearby fires (less than 30-40 km from airport) frequently led to ground traffic jams as aircraft waited
for refill opportunities. Aerial operations were being strangled by ground limitations.
Our group was unable to gain outside interest in possible solutions. Consequently, a grass roots
community led and funded project team designed, constructed, and tested a skeleton project. This
reduced single aircraft refill time to 1.75 minutes for a single aircraft and under 3 minutes for two
aircraft simultaneously via two hydrants. In the Pit Road fire of early March 2016 (25 km west of
Denmark) operations with four water bombers demonstrated sustained ability to air lift over forty
tonnes per hour of water to the wind-driven fire which was quickly brought under control in about
two hours. High rate aerial delivery coupled with coordinated ground crew activities subsequently
extinguished the fire after night fall.
This first “trial by fire” demonstrated the effectiveness of high rate aerial delivery, but also
demonstrated issues with aircraft-driven dust and stones in refill areas, ground traffic jams due to
inadequate taxiways and limitations of current water storage capacity, now only 5 hours at the
newly-increased refill rates. Funding proposals to address these issues have been submitted in costsharing grant applications seeking Royalties for Regions money for regional development.
Approach, performance results obtained thus far, lessons learned and proposed improvements are
discussed in the following sections.
Problem Statement
Denmark and West Coastal Great Southern are forested, hilly, have winding roads, growing
population, and tourist influx in summer frequently exceeding 10,000 visitors who are densely
packed in some areas. The risk of catastrophic bushfire in summer is increasing and possible
consequences in loss of life, property, environment, value, and future opportunities would be
devastating. Capability to fight such a large fire is limited and consequences of limitations have been
demonstrated by the recent tragic Yarloop fire.
High rate aerial bombardment via water bombers has been identified as essential to early fire
control and limitation. Water bombers launch flights from Denmark Airport which would be closest
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to the areas of greatest threat and consequence. DPAW/DFES can bring up to 6 water bombers to
the airport.
THE PROBLEM: for nearby fires aircraft cycle times are very short, < 10-15 minutes, and airplane
traffic jams form on the ground waiting for refill. We have seen three out of four waiting on the
ground lined up for water. Previously water bombers were filled one at a time using a 5.5 HP petrol
pump to pressurize tank water and deliver it down a 65 mm diameter 30 meter long lay-flat flexible
line to the water bomber. Best fill times recorded were 5+ minutes and this could stretch to 7-8
minutes if kinks in the line, sometimes numerous, were not quickly removed.
Our technical analysis of line pressure losses and the pump performance curve (pressure rise vs. flow
rate) showed that the long, skinny refill line choked the flow down to 600 litres per minute
(maximum) under best conditions. So technically speaking the problem arose from
 Pump limitations – insufficient capacity.
 High friction losses due to fill line being too small and long.
 Failure of ground crews to recognize the huge choking effects arising from hose kinks.
Project Goals and Technical Approach
Objectives and Benefits
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Cut the refill time in half. Reduce refill time from previous 5-7 minutes to 2.5 minutes.
Improve “water on fire per hour” capability.
Create ability to refill two aircraft at the same time. Further improves water bomber
throughput.
Redundancy in water pumping capability. Improve overall reliability: new electric pump
with petrol-powered fire brigade pumps so that there is 100% back-up for failure in either
power source.
Improve human factors. Shorten heavy flexible supply hoses which must be dragged to and
from aircraft. Ease system operations. Eliminate need to repetitively pull-start the petrolpowered pump normally used for loading water bombers at the airport.
To understand the technical approach which involved systems engineering, flow pressure drop
analysis, and consideration of pump characteristics, it is helpful to consider the following simplified
problem. Consider a tank, a pump, and a delivery line to a receiver (aircraft). To double the flow by
using a “better” pump but same delivery line, how much more power is required? Answer: Double
the flow creates FOUR times more pressure drop in the same line, so that EIGHT times more power
would be required. Since our existing portable petrol pump is 5.5 HP, a total of 44 horsepower
would be required to meet the flow requirement.
The laws of hydraulics show that the most cost effective solution is to greatly enlarge the supply
line diameter to reduce friction losses at higher flows (particularly for the case of filling TWO aircraft
at the same time). Then carefully match the system requirements to an appropriately selected
electric pump to match the selected maximum flow and preferred low pressure drop. The resulting
system plan view for Denmark Airport is shown in the sketch that follows.
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Initial System Layout showing existing tank, new pump, new underground supply lines to two
hydrants. Lay-flat flex lines from hydrant to aircraft were increased from 62 mm (shown) to 75 mm
diameter to further minimize pressure drop, but remain the major element of pressure drop in the
revised design.
The key system elements are as follows:
 150 mm diameter PVC line from tank shut off valve to pump inlet.
 5.5 kw (about 7.5 HP) high flow low pressure centrifugal pump driven by three phase
electric motor. Normal operation requires a pump pressure rise of only about 120-130 kpa
(about 22-24 psig), but peak flow exceeds 2500 litres per minute. The low pressure permits
minimal horsepower thus substantially reducing pump cost to about $4400. A bypass valve
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was installed so that in the event of electrical failure, water can pass through and around the
pump to hydrants where standby petrol pumps can be attached to deliver water to aircraft.
150 mm diameter PVC supply lines underground to two “hydrants” consisting of upright 150
mm PVC lines, elbows, reducing to 75 mm ball valves, thence to standard 75 mm quick
disconnect fittings common to local fire equipment and the water bombers.
12 meter 75 mm lay flat flex lines to water bombers. Substitutes are now being sought
which are more kink resistant. Ground crews have been trained to immediately remove
ALL kinks from hoses, particularly important at the high refill rates used.
SES training session showing aircraft and two hydrants
Pump, piping with pump bypass valve, foam cart, control panel inside shed
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Results Achieved
During training exercises we did one full refill cycle and demonstrated that a 3000 litre Air Tractor
could be filled, empty to full, in one minute forty five seconds, substantially better than our initial
goal of two minutes thirty seconds. This corresponds to a refill rate of about 1700 litres per minute,
about triple the old rate.
Subsequently in the Pit Road fire of early March 2016, with a bit of practice to quickly remove hose
kinks, ground crews showed they could do a connect-refill-disconnect from aircraft stop to aircraft
start taxi in the same one minute and forty five seconds. As best we could determine, refill of two
aircraft at the same time could be achieved in about two minutes and thirty seconds, a combined
flow rate of about 2400 litres per minute.
Duration of aerial operations for the Pit Road fire was about two hours, the first forty five minutes
with two aircraft from Albany, and then with arrival of two more aircraft from Manjimup, four
aircraft operated for an hour and fifteen minutes until dusk. By monitoring water consumption
using the tank level indicator we established that a maximum demand the aircraft were air lifting
over forty tonnes per hour (forty thousand litres per hour) to the fire on a sustained basis. This
meant that an aircraft was passing over the Denmark CBD outbound or inbound about once every
two minutes. Residents watching said it “sounded like an aerial freight train” passing overhead.
The fast and heavy aerial attack is credited with quickly containing the fire which was on a track to
grow rapidly based on afternoon winds, and for saving a home and garage due to precision drops
supporting ground crews.
Follow up reports from fire fighting personnel and as collected by the local press are summarized in
the two pages that follow along with a “Report to the Community” after Phase 1 construction was
completed .
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PROGRESS REPORT TO COMMUNITY [February 2016]
New System Quadruples Water Bomber Refill Rate
100% Community Funded and Supported
Phase 1 completed December 2015 in preparation for high risk bush fire season
Problem
 Water Bombers operating out of Denmark Airport are the primary protection for
Bush Fire Brigade personnel on the ground as well as saving homes and structures
with precision water drops.
 For fires within 10 km of Denmark flights are so short that airport refill facilities
clogged with aircraft waiting in the refill area. The airport “saturated” with just two
fire bombers.
Project Benefits
 Cut single aircraft refill time in half
 Refill two aircraft at once with two high-flow hydrants
 Redundant pumping capability Large electric pump plus dual petrol back-up pumps
 Improve operations for ground crews
How did we get it started?
 Project launch followed by work contributions from Denmark Airport Association
and Denmark East Bush Fire Brigade to design system and install shed, pump,
foundation, piping, and complete system testing totalling in excess of 500 work
hours.
 Financial and non-cash contributions totalling about $12,000 to cover equipment,
parts, services and materials. Many thanks to our community contributors!
Cash Contributions
Members - Denmark Airport Association Members - Denmark East Fire Brigade
Denmark IGA Supa
Thornton’s Hardware
Denmark Pump Service
Dept. of Parks and Wildlife (Walpole)
Denmark Pharmacy
Ocean Beach Fire Brigade
SES
Somerset Hill Bush Fire Brigade
Denmark CO-OP
And a few thoughtful local residents
Contributions of Parts, Materials, and Supporting Services
Thornton’s Hardware
Denmark Earthmoving
Shire of Denmark Palmer Earthmoving Bouwman Contracting
Next step - Continue working with Shire to finish the job in 2016
 Pave gravel area around hydrant no. 2. Stop blowing dust, sand and gravel at ground
crews and eliminate muddy refill area.
 Erect barriers to protect ground refill crew from 200 km/hr prop blast created when
7.3 ton 1200 horsepower water bombers start to taxi away from refill area.
 [And add additional water storage capacity and taxiway capacity.]
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Lessons Learned
The project team was gratified that all the performance technical objectives were surpassed in terms
of flow rate, refill time, and aircraft throughput rates. Most important, the benefits of higher
throughput were dramatically demonstrated by quick fire suppression and “saves” of
environmentally sensitive areas and private structures.
However, experience is always a good teacher, and the following issues were identified for
corrective action.
Ground operations at the second hydrant, surrounded by hard pack gravel (due to limited available
funding and time) exposed ground crews to rocks and dust flung up by the heavy departing water
bomber as shown below.
When filled aircraft power up to depart, gravel, dirt, and debris are kicked up with up by 200 km/hr
prop blast. This aircraft is about to turn right to enter the runway, blasting the ground crew. This
problem must be addressed before the facility can be safely and effectively utilized.
The high throughputs achieved quickly reduced water levels in the 220,000 litre water tank which
has a bit over 200,000 litres usable. At consumption rate of 40,000 litres per hour (four aircraft) the
onsite stored water would be depleted in about five hours. This time is inadequate to establish a
“supply chain” of tank trucks to keep the tank full in the event of a major fire. Measurements during
tank refill the following day showed that one hour is required per truck cycle, or that four tank trucks
are required to meet the demand rate. Discussions suggested we need to have at least twelve hours
of water on site (one day of daylight, required for flying) plus overnight to establish such a supply
chain.
Aircraft do not return from the fire in uniform, equally spaced time intervals. At times the aerial fire
spotter will hold aircraft when attention shifts to another target area at which time the holding
aircraft are formed into a line to drop over a particular line or area. After doing so, they arrive back
at the airport at about thirty to sixty second intervals. They sort out landing sequence using radio
calls, but all arrive for refill within a few minutes creating traffic jams on the ground created by
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inadequate runway access. Additional taxiway resources are needed due to the layout of the
airport.
Finally, ground crews have to be reminded to keep taking kinks out of the flexible supply lines. It is a
tiring business and a nuisance. We are addressing this by evaluating alternate flexible hoses as well
as exploring ground marking schemes that would permit pilots turning into refill position to more
accurately place their aircraft so that the refill port appears over the same piece of pavement every
time. If they stop short, extra hose length leads to kink formation. If they stop long they have rolled
out of reach and must circle again, usually stopping much too short “to be sure” but causing more
problems with hose kinks.
Phase 2 Project Improvement Plans
Based on debriefings, problem assessment, and evaluation of options we have formulated a three
part “completion project” that will address the issues above as well as permit further improvements
in throughput which would be required in the event of a major, catastrophic-sized fire.
Phase 2A) Ground personnel are at risk when bombers power up to return to the runway they
throw dirt and gravel at ground crews. This project will fund asphalt where ground personnel are
now hit by flying gravel/rocks, and also construct 2 meter wide “blast walls” at three locations to
protect ground personnel.
Phase 2B) Existing 200K litre water tank contents can be consumed in as little as 5 hours by four
aircraft. A larger 280K litre water tank will be installed to permit up to 12 hours for the refill truck
supply line to be established (4 trucks per hour @ 10K litres/truck) before water is exhausted.
Phase 2C) High bomber throughput has caused ground traffic jams restricting throughput. Existing
taxiways must be widened and paved to provide better access to and from the runway now served
by only one paved taxiway.
The improvements are illustrated in the sketch on the following page.
Proposals have been prepared and submitted to the Great Southern Development Commission
which is responsible for distribution of funds from Royalties to Regions and delivered via the
Community Chest Program and Regional Development Scheme. These detailed proposals lay out
objectives, schedules, technical approach, and projected costs for completion. They combine a
team comprised of the Shire of Denmark, Denmark Airport Association Inc and East Denmark
Bushfire Brigade which has thus far demonstrated the ability to “get the job done” quickly and cost
effectively. Results of these submissions are expected in June, 2016.
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