In the past, many departments viewed skid-mounted pump and tank units as something to be used by the state forest service or rural fire districts because of their small tank sizes and limited options. But skid mount uses have grown over the years, and that view has changed. Departments that look closely at these compact, self-contained firefighting packages will find that skid mounts offer some real value.

One of the most important advantages of skid mounts is a low purchase price. Some units list for under $7,000 and include a variety of premium components, including brand-name engines and pumps, corrosion-resistant tanks, and electric rewind booster reels. And because all the components are mounted on rigid bases, they can be transferred easily from one chassis to another.

Another big advantage is that skid-mount units are easy to operate and maintain. They can be put into action by a single person and often respond with a crew of only one or two. That is especially important for departments with limited staffing or delayed volunteer response. The pump controls are grouped together at the rear of the apparatus to provide easy access. Some designs also have duplicate controls in the cab to allow pump-and-roll operation using remote-controlled monitors. Because the engine, pump and valves are out in the open, they are easy to check and maintain. Well-known manufacturers make the most of the major components, so parts and service are readily available.

The basic skid-mount design mounts all the components on flat bases, which helps provide low centers of gravity and low overall heights. That's a big advantage when operating on side slopes or uneven terrain where the possibility of rollover accidents is a special concern. Skid-mounts also tend to concentrate the weight along the center axis of the apparatus rather than to the sides, giving additional side-slope stability. The low height allows them to pass under trees with overhanging limbs or go into parking structures with restricted overhead clearances.

Finally, some departments have found they can get points from the Insurance Services Office for their skid-mount units. To do this, the apparatus must meet certain requirements for the pump, tank and loose equipment. Additional requirements regarding the station location, staffing and other factors may apply.

Plenty of options

One thing that distinguishes current skid-mount units is the array of optional configurations and equipment. While older units may have been limited to simple pumps, tanks and plumbing, newer ones include a wide variety of compartments, foam systems, hoses, lights and other options.

Compartments are one of the most common options specified by customers. They range from simple underbody storage boxes to complete drop-in bodies with integral water tanks. Some manufacturers offer one-piece bodies of polypropylene designed for corrosion and impact resistance. Others offer modular compartments of aluminum designed to provide unlimited storage configurations. The best ones keep everything low.

Class A foam systems are another common option specified on skid-mount units. Nozzle-aspirated foam can penetrate and coat fuels to double the effectiveness of plain water. It results in quicker extinguishment and fewer rekindles to make the tank water last longer. Several types of foam systems are available.

Various hose reels and trays give the flexibility to handle many types of fire situations. Low-profile booster reels help reduce the overall height, while larger-diameter reels hold long lengths of hose needed for some wildland situations. Short, preconnected structure attack lines let firefighters knock down roof and deck fires with higher flow rates.

Area lights are a necessity for safe operations at night. They should be mounted on both sides and at the rear and aimed downward at an angle. Lights that run on vehicle power can give good illumination. One manufacturer offers several engine-driven pumps with built-in generators to provide line voltage for brighter illumination. Protective guards and vibration-isolator bases can help lights last longer under tough off-road conditions.

Departments that previously ignored skid-mount units, now have some good reasons to take a second look. Many advantages combined with lots of options make skid-mounts an attractive way to handle many fires.

NFPA Standards for Skid Mounts

Apparatus equipped with slip-on or skid-mount pump and tank units are covered under two NFPA standards depending on the application.

NFPA 1901 applies to apparatus primarily used for structural fire suppression and other non-wildfire duties. Although most skid-mount units are too small for this application, a few can be used on initial attack apparatus and must meet those requirements. See NFPA 1901 Table 4.2.2 for the applicable chapters. Note Section 15.12 for special requirements.

NFPA 1906 applies to apparatus primarily used for wildland fire suppression. This is the most common use of skid-mount units, and the entire NFPA 1906 standard applies. Note Section 8.11 for special requirements.

Some of the key differences between the two standards are that NFPA 1901 has higher minimum requirements for pump ratings, tank size, hose and miscellaneous equipment, while NFPA 1906 has tougher standards for side-slope stability, ground clearances, and angles of approach and departure, among others. Departments that plan to use skid-mount units for both structural and wildland fire duties need to understand the requirements of both standards.