The Apparatus Architect-November 2013 Ground Ladders-One of the Most Important Tools

Your department has just determined that it is time to replace the 1995 100 foot quint rear mount ladder with a new apparatus.  The current vehicle is equipped with 158 feet of portable ground ladders including two 35 foot three section extension ladders and several 16 foot roof ladders. While the apparatus committee is meeting with prospective bidders one of the salesmen mentions that the NFPA 1901 Standard now requires only 85 feet of ground ladders on quints and suggests that the group decide which is more important the compliment of ground ladders or the desired 500 gallon booster tank on the truck.  How can you possibly ladder all four sides of a two and half story private dwelling and the roof with 85” or 115”?  The reality will not support that.  ( In aerial ladder classes that Tom and I have done we will ask how often do you use your portable ladders vs. the aerial device itself and the response averages out to be 7 to 1 for every one time that most fire departments use the aerial device we  they will use ground ladders seven times. )

When questioned on this issue one of the senior members suggests that the members review the first due response area to evaluate the structural conditions. While some on the apparatus committee thought this to be a waste of time, others indicated that maybe the 500 gallon booster tank was a nice to have feature, but not critical in the department’s operations. After a few weeks of touring around the response area and measuring some of the building heights a number of concerns came to light. Since the 1995 quint was placed into service there have been several new townhouse complexes that are three stories in height from the A side but due to terrain are four to five stories high on the C side of the structure.  In addition some previously undeveloped farm land was turned into a residential sub-division with five to six thousand square foot Mc Mansion’s with limited access for aerial ladder trucks.

After considering the building and demographic changes to the response area the truck committee decided to reevaluate the importance of ground ladders on the new apparatus. The NFPA 1901 requirements for the ground ladder compliments on a quint or non-quint ladder have remained at 85 feet and 115 feet for a number of years.  These suggested ladder compliments are a minimum and must ultimately be determined by the department based upon the buildings in their response district, apparatus assignments, operating guidelines and past fire ground experiences.

The standard ground ladder compliment on most pumpers is a 14 foot roof ladder, 24 foot extension ladder together with a 10 foot folding ladder.  In addition to the traditional mounting on the right side of the apparatus ground ladders can be carried on a hydraulic rack, enclosed in the body or through the water tank.  The hydraulic rack works well when there is no overall travel height concern and permits longer ladders to be carried.  Departments that wish to have the ladders fully enclosed within the body must sacrifice either compartment space or contend with a three section extension ladder if sufficient space is not available to accommodate a two section ladder.

 

Aerial ladder and towers are commonly designed with a fire pump, booster tank and a hose bed for supply line.  The hose bed area may be located ahead of the aerial turntable or on the side of the body over the lower compartments.  In either event, the quantity of ground ladders you wish to carry on the apparatus is determined by the available space under the turntable and outside of the body based upon the water tank size, depth of the body compartments, amount of supply line carried and the location of other components such as hydraulic oil reservoir and the water way piping. There is only so much space if you fill it up with a pump, tank and hose, you can not fill it up with portable ladders.   

One aluminum ground ladder company in their catalog lists a two section 35 foot extension ladder as having a closed length of 20 feet, 1 inch with a weight of 139 pounds. A three section version of the same ladder is 15 feet, 8 inches long and weighs 170 pounds. A truss style version of the two section 35 foot ladder has a slightly higher banking thickness but is only two pounds heavier than the solid beam, pumper style extension ladder.  The ground ladder banking on any aerial device can be determined in conjunction with the apparatus manufacturer’s body engineering group and can provide suggestions to enable your apparatus committee to maximize the available space to carry portable ladders.

The College Park, Maryland Fire Department operates as Station 812 in Prince George’s County with two engines, rear mount ladder, foam unit, haz mat support unit, two ambulances and a medic unit from their station. Due to the building and structural conditions on the University of Maryland campus and surrounding response area the department has outfitted their engines and a county provided ladder truck with a diverse compliment of ground ladders.

Prince George’s County had recently placed into service two Pierce Arrow XT 105 foot rear mount ladders that carry a total of 266 feet of ground ladders including a 45 foot bangor ladder, two 35 foot extension ladders together with two 16 foot roof ladders and a 28 foot extension ladder carried on the right side of the apparatus.  The ground ladder banking is clearly marked to indicate the length of each ladder. A simple solution may be to label the inside portion of the ladder guard with reflective numbers in addition to marking the butt spurs on the ladders with the appropriate length of each ladder.

Ground ladder storage areas aerial apparatus are largely dependent upon the packaging of other chassis and body components. The banking arrangement of on beam or flat positions may also be influenced based upon the maximum travel height of the apparatus, so when beginning the process of specifying a new apparatus it is always a good idea to confirm the principle dimensions of the apparatus bays including ramp angles and other height restrictions in the response area.

 

 

Tractor drawn ladders have a distinct advantage of having almost unlimited space to carry portable ladders both inside of the trailer and on each side of the body compartments.  Where there is a requirement to carry a number of longer roof and wall ladders in addition to multiple two section extension ladders the tractor drawn aerial can easily accommodate over 300 feet of portable ladders with room to spare.

When designing any new aerial device careful consideration must be given to determining the appropriate number and configuration of portable ground ladders.  As the old fire service proverb goes: “You can stretch a hose, but you cannot stretch a ladder”. While operating on the fire ground the proper placement of ground ladders is of vital importance for the safety of our personnel as well as any potential victims within the building. No other agency is responding to our incidents is carrying portable ladders, make sure you have pre-planned your first due area to insure that your rigs are carrying the correct compliment of ground ladders.

Photos for use in November, 2013 Apparatus Architect:

All photos by Tom W. Shand

Photo #1: AA November Photo #1

The College Park, Maryland Fire Department engine apparatus carry a compliment of portable ladders mounted outboard on the right side of the apparatus.  Note the placement of the ladders above the standpipe hose trays and that the ladders do not extend past the rear body.

Photo #2:

AA November Photo #2

Ground ladders may be carried both on beam and flat inside of the body depending upon the space available and banking thickness of each ladder. Note the placement of the roof hooks at the top of the ladder bays.

Photo #3:

AA November Photo #3

Prince George’s County Truck 812 is equipped with 266 feet of ground ladders both at the rear and right side of the apparatus. The ladder balance points are marked on the beams with blue reflective tape.

Photo #4:

AA November Photo #4

The Suffern, New York Hook and Ladder Company carries over 330 feet of ground ladders including multiple 24, 28 and 35 foot extension ground ladders.

Photo #5:

AA November Photo #5

The Fairfax County, Virginia Fire Department marks the inside of the ground ladder bay with reflective tape to indicate the appropriate length of each ladder carried on their truck company units.

 

Apparatus Architect November, 2013

By: Tom W. Shand and Mike Wilbur