Shorelines: More than Just Extension Cords

By Mark A. Farley, CFRN
Flight Nurse
HealthNet Aeromedical Services Base 9


When unplugging your ambulance or aircraft, have you ever noticed the shoreline connection felt a little warm? If so, do you realize this can potentially be a serious problem?

Even if the connection does not feel warm, an inspection of the cord and its connections
still needs to be done. This cord is essential to the Mission.Ready. philosophy we live by each day.

Ambulance manufacturers began using products for shoreline connections in the early 1970s. This equipment was equivalent to standard RV hardware that would accommodate the load of a tricklecharging for system batteries, a suction device and a hand-held radio.  This work load would pull less than 500 watts and a 15-amp residential cord could handle the demand easily. Shorelines are connected to many things today that are considered “parasitic loads.”

Some examples at minimum are a 10-amp charger for the chassis batteries, chargers for cot batteries, cardiac monitor, ventilator, suction, thermal angel/buddy lite, refrigerator and possibly a block heater.  All of this adds up!  The next time you remove the shoreline
cord and it feels warm, it is a safe bet it is delivering current more than its recommended capacity.
Always examine shoreline cords at both ends and the shoreline receptacles on both ambulances and aircraft. A safe cord should be firmly attached to its plugs on both ends. If you find cutting of the outer and inner jackets exposing bare copper, remove the cords from service immediately and notify the base lead.  Crews must be familiar with the breaker panel in their ambulance and should know where it is located and how to reset the panel. It should contain at least a 110-volt circuit breaker, which looks like a
toggle switch. There should be a number, either 15 or 20, on the visible part of the breaker which indicates the maximum amount of a 110-volt current the breaker will handle before it trips. The constant load rating for shoreline should amount to less than half of the breaker’s trip limit.
Cords should also be permanently labeled every three to four feet with the kind of wire it contains. For example, a cord that handles a max of 15 amps should be labeled 14-3 AWG. This indicates three 14-gauge wires. A cord that handles a max of 20 amps should say 12-3 AWG.  This means three 12-gauge wires.  A 12-gauge cord protected by a 20-amp breaker in the station or hangar and a 20-amp breaker in your ambulance or aircraft would be optimal.
It is recommended that ambulance and aircraft shoreline cords be replaced once each year. Each time the cord is plugged and unplugged the ends arc slightly. This arc causes some wear on the metal and creates some minor damage.  The amount of times the cords arc when plugged in wears the contacts, thus making the contacts less and less reliable when the cord is utilized over time. Cords do get wet and are run over from time to time by vehicles more than five tons.  Make it a habit to pull cords out of the drive path of
vehicles.  Habits are reliable, even when we are tired.