Detachable chairlift

Detachable quad chairlift grip. (Chair is on a sidetrack). This type of grip can be seen on Dopplemayr high speed quads built between 1985 and 1995.

A detachable chairlift or high-speed chairlift is a type of passenger aerial lift, which, like a fixed-grip chairlift, consists of numerous chairs attached to a constantly moving wire rope (called a haul rope) that is strung between two (or more) terminals over intermediate towers. They are now commonplace at all but the smallest of ski resorts. Some are installed at tourist attractions as well as for urban transportation.

The significance of detachable chairlift technology is primarily the speed and capacity. Detachable chairlifts move far faster than their fixed-grip brethren, averaging 1,200 feet per minute (14 mph, 22 km/h, 6 m/s) versus a typical fixed-grip speed of 500 ft/min (6 mph, 9 km/h, 2.5 m/s). Because the cable moves faster than most passengers could safely disembark and load, each chair is connected to the cable by a powerful spring-loaded cable grip which detaches at terminals, allowing the chair to slow considerably for convenient loading and unloading at a typical speed of 200 ft/min (2 mph, 4 km/h, 1 m/s), a speed slower even than fixed-grip bunny chairlifts.

Another advantage of detaching chairs is the ability to remove chairs during severe weather in order to reduce stress on the rope and towers. Furthermore, operating the unladen rope during extreme weather is effective at preventing—or greatly reducing—ice and snow accumulation on the sheaves and rope. This saves considerable time, expense and hazard when opening the chair for operation, which would otherwise require workers to climb each tower and chip away ice and shovel snow.

Chairlifts are made in a variety of sizes, carrying from 2 to 8 passengers. All chairs on a given chairlift usually have the same capacity. Slang terms for the different sizes include "doubles", "triples", "quads", and "six packs". Detachable chairlifts may also be described as "high speed" or "express", which results in terms such as "high speed quad" and "express quad".

Some detachable chairlifts have so-called bubble chairs, which add a retractable acrylic glass dome to protect passengers from weather.

An alternative system for reconciling slow boarding speeds with fast rope speeds is the carpet lift: the chairs move at full speed even through the terminal. Boarding passengers are progressively accelerated on a system of conveyor belts of carpet-like material until nearly matching the chair speed.

On Sunday, 26 December 2004, Lech am Arlberg and Schröcken in the Bregenzerwald, became the first chairlifts to have heated seats when five Doppelmayr detachable chairlifts offer skiers the added luxury of a warm seat on the uphill trip.

History

Doppelmayr

The detachable chairlift didn't start with a chairlift, rather, it started with the Platter lift in 1908, as the sticks left the cable and attached when someone loaded onto the stick. A detachable two person chairlift was installed in Cairngorm Mountain, Scotland in 1961. In 1981, the first ever high speed detachable quad in the world was installed, the Doppelmayr-built Quicksilver SuperChair at Breckenridge Ski Resort in Colorado, in 1981. This lift was relocated in 1999 to the Owl's Head Ski area in Quebec. Until 1985, this was also the only detachable quad in Colorado when Vail Ski Resort installed four Doppelmayr high speed quads. The original grip was slightly modified later before the Vail quads were built. Known as the Spring Series, these grips were known as DS-104 grips on high speed quads and DS-108s on eight passenger gondolas. In 1995, a newer grip was introduced called the Torsion series. Torsion grips were called DT-104 if on a high speed quad, DT-106 on a high speed six pack, or DT-108 on an eight passenger gondola. The Torsion grip is still made today as Doppelmayr CTEC's primary grip option.

Unlike Poma's grips, Doppelmayr grips are double position grips. When the chair enters a terminal, the angled roller is pushed down by a metal strip, which opens a grip jaw. The jaw remains open until the chair reattaches to the cable upon departing the terminal. Grip clamping force is measured just prior to the double position grips reattaching to the haul rope while a carrier (chair) is exiting the terminal, in contrast to Poma's grips, in which grip force can be measured as the grip travels through the contour. Insufficient grip force triggers an alarm and brings the lift to a halt before the carrier reaches the first breakover tower after the terminal. Because of this design, most Doppelmayr detachable lifts are designed to allow operation in reverse. This allows a grip force-alarmed grip and carrier to be backed into the terminal for inspection or removal.

The original terminals on the Quicksilver Quad were all completely enclosed, but in 1985, in time for the Vail Ski Resort high speed quads, the terminal design changed to what is now classified as a CLD-260 terminal. These and the older terminals were the only types of terminals to use chains instead of tires for contours. In 1989, the old design was officially retired with the addition of the Avanti high speed quad at Vail, and a new design, called the UNI, was introduced. This design was utilized from 1989 to the last year of the DS-104 grip in 1994. In 1992, the design was changed slightly mainly in the entry funnels area. With the introduction of the Torsion series came the UNI-M terminal, which underwent a number of minor cosmetic changes between 1995 and 2002. Currently, two options are offered, the UNI-G terminal, and the UNI-GS terminal, which can be distinguished through the appearance of the end windows.

Poma

Poma entered this market within two to three years of the Quicksilver Quad's installation. Although hard to prove, the earliest known Poma quads are from circa 1985, such as the Coney Glade at Snowmass, the high speed quad at Mission Ridge (installed in 2005, ran at Winter Park Resort from 1985 to 2005), and others. Many of the original high speed quads they built were known as Alpha Falcon lifts, because they utilized a Falcon terminal with an Alpha drive unit at the far end. Very few lifts exist with this style. Later on, the Falcon drive terminal was modified to house the bullwheel inside the main terminal structure itself, eliminating the need to run the cable through the terminal. Poma was also slower at introducing tire contours over chains, and it wasn't until 1992 that tire contours were used by the company with the introduction of the Challenger terminal. This terminal would undergo changes with the windows before officially retired in 1998. At that time, the new Omega T-Grip came out and a new terminal known as the Phatboy (homophone and pronounced Fat-Boy) was introduced for it. It was replaced by a newer variant that mainly modified the windows on the ends in 2003.

Unlike Doppelmayr, the Poma grips are single position. In such method, they are pressed down, which opens the jaws to detach the chair, and then the jaws close and the spring is released. The process is reversed for attachment. This design allows grip force to be measured as the grip travels through the contour, and for the lift to come to a stop before the grip is reattached to the haul rope if insufficient grip force is detected. Unlike Doppelmayr lifts that check grip force while a grip and carrier are leaving the terminal, most Poma detachable lifts are not built to operate in reverse because a grip force failed grip can be brought to a halt within the terminal.

Poma is also known for building some very unusual lifts, mostly at Breckenridge Ski Resort, which include North America's only double loading chairlift (Quicksilver Super6), the first high speed lift in Colorado with a midway load (Peak 8 SuperConnect), and the highest lift in North America (Imperial Express SuperChair) at 12,840 feet and highest high speed six pack in North America (Kensho SuperChair) at 12,300 feet.

CTEC/Garaventa CTEC

Garaventa CTEC entered the Detachable lift business in the 1990s. They have built detachable lifts at many resorts, such as Grand Targhee, Stevens Pass, Deer Valley, Park City, Squaw Valley, Stratton, and Attitash. They constructed lifts until 2002 when they merged with Doppelmayr. Some Garaventa designs are used to this day.^[1]

Present

Leitner-Poma

Leitner-Poma is the present day version of Poma, as joint venture in the United States. In Europe, Poma and Leitner operate as separate ventures. They continue to make all types of detachable chairlifts using their Omega Chair, Leitner Grip, and Omega Terminal.

Doppelmayr/CTEC

Doppelmayr CTEC, the merger of CTEC, Garaventa, and Doppelmayr globally, continue to make Garaventa and Dopplemayr Carriers, their UNI-GS/UNI-G (Europe) terminals, and the Torsion girp today.

References

↑ http://www.skilifts.org/old/chairlift_facts_liftid_dctec.htm