Basic Elevator Indentification


CarolinaFireJournal - Ed Henry
Ed Henry
01/11/2011 -

Consider these facts. There are approximately 600,000 elevators in the United States, or about 12,000 in each state. There are 120 billion rides on elevators and escalators each year. Out of those 120 billion rides, about 10,000 people end up in an emergency room due to elevator- or escalator-related accidents. These accidents are caused by tripping, by clothing getting caught, by being hit by closing elevator doors or by falling down an elevator shaft when trying to exit a stalled elevator car.

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In today’s fire service, elevator emergencies and rescues seem to be out of the normal day to day operations of most fire departments. This type of emergency/rescue is classified as low frequency and high risk. With that being said, we will discuss; the difference between the elevator emergency and the elevator rescue. Think of it this way, if you are in the elevator and it stops, unless there is some type of medical issue or the elevator car is compromised, it is a mere inconvenice to the occupants and not an emergency.

The modern elevator trade has three classifications of elevators. Only the basics of all three will be discussed, as the course is between 24 and 40 hours long, depending on how much rope work the customer needs in the class. These classes usually include escalator emergencies as well.

The oldest, the drum style, is no longer produced but many are still in service. The newer version of the drum style is called the traction elevator. In the trade it’s termed “roped,” although it’s slang, hemp rope has not been used in decades, current code requires all elevators use steel cables.

Traction elevators are broken into two types, the passenger elevator and the freight elevator. The “new kid on the block” is called the MRL or machine room-less elevator, and this will be discussed later in the article and in depth in future articles.

The drum elevator operates like a winch. The machine room could be in the basement, thus creating a two to one mechanical advantage, or in the top of the high rise in its own area or machine room.

The electric traction elevator has a counter weight that runs opposite the car that is in the shaftway on its own rail system. The machine room is always above the hoistway on the top floor, or in its own room constructed on the roof.

The gearless traction elevator is similar in design, with a few exceptions, to the components. You will find this system in high rise buildings, usually 20 stories and more, and in most cases these are the “express” cars, as these can reach speeds of 35 mph. They are also referenced as the “blind shaft” elevator and this is where the rope rescue will be needed for the rescue of trapped people.

The hydraulic elevator or the “hydro,” comes in two basic styles. The rule of thumb here is that the piston will not be longer than five to seven stories in height. The piston has two styles — solid or telescopic depending on what’s in the ground. The telescopic is used in areas with a shallow water table, tunnels below, ledge in the ground and things of that nature. The “pump” room can be next to the shaftway or many yards away and in some cases, even on different floors all together. One more reason to know your district.

The freight elevator has five classes, but again for this article we will discuss the basics. A true freight elevator will usually be of the geared traction style. The doorway at the hoistway will have the tell tale signs of the vertical bi-parting doors.

The residential elevator, or “swing door” style, is what you would find in a commercial business that needed to comply with the Americans with Disabilities Act. In some cases the hoistway is built outside the building and in others, it’s added to the interior of the building. You can also find the “swing door” elevator in many high end homes. Some of these home elevators have the elevator interlock, while most do not.

Something to think about, responding to a home fire, you are searching in low or no visibility and you force open a door — make sure that you sound for a floor. Because you could have forced open a basic house door that leads to an elevator shaft, which in turn could lead to a substantial fall. This shows the dangers of some homes with elevators that do not meet codes for safety standards for the elevator interlock.

All updated and newly installed elevators will be compliant with the Americans with Disabilities Act. I would bet that everyone has been in a compliant elevator at least once, but did not know it or really give it a second thought. The call button on the main floor will have a star next to it and as the elevator car moves from floor to floor it will make a gong or buzz type of noise, this is for the seeing impaired to help them reference that the car is moving and so they can count the floors as it moves up or down.

The machine room-less (MRL) elevator, as referenced in the beginning of the article is worded as “the new kid on the block,” but in reality these have been around for many years. These were designed to replace the “hydro.” The pros to this are lower insurance ratings due to the building owner not storing a few hundred gallons of flammable liquid in the building. The machine room takes up less area, meaning more rentable space for the building owner. The lack of hydraulic oil smell in the building and thus no over spill or broken lines to ruin anything in the building and that with no spills, is less chance of a worker or civilian slipping or falling, equaling no law suits. The other benefit is the system uses less power.

The cons to this unit is that it costs more for the installation and it is somewhat new to the United States, therefore good installations and technicians are far and few between. The motor unit is made up of three electric motors with two being the main pulling power units and the third for heavier loads and for the use of lowering the car. The cables are replaced with belts. The unit is mounted on the rails just above the last upper floor served.

Now you should be able to identify the different types of elevators. In the future we will discuss ways to better understand the use of elevators at high rise alarms, fires and troubleshooting the call with stuck elevator cars. 

 Terminology and definitions of elevators

 (These are not all the terms and components of an elevator, only some key terms.)

Hoistway: The shaft encompasses the elevator car. Generally serving all floors of the building.

Platform: A heavy steel frame surrounding a cage of solid metal. The top of the car frame is called the “crosshead”. Cabled elevators are usually suspended from the crosshead.

Car: This is where passengers and freight ride.

Elevator car door: attached to the car and travels through the hoistway with the car

Hoistway door: All floors serviced by an elevator have their own set of hoistway doors.

Guide rails: Tracks in the form of a “T” that run the length of the hoistway, that guide the elevator car.

Guide wheels: A set of three wheels, with at least four sets on each car, that roll against the guide rails; these stabilize the car during movement.

Counter weights: A tracked weight that is suspended from cables and moves within its own set of guide rails along the hoistway walls.

Interlocks: These are the locks on the doors in elevators.

Governor safety: Emergency braking mechanism that stops the car by wedging brakes into the guide rails when over speeding has occurred.

Brakes: part of the governor safety system that stops the car from falling or over speeding.

Pit: The lowest part in an elevator system.

Machine room: where all the motors and electric components for the elevator(s) are housed.

Sheaves: trade name for pulleys

Emergency escape hatch: used when the car is stuck to remove occupants.

 

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