On a recent trip to France, SAM visited the studios of Denis Creissels, conceiver of some of the most avant-garde of today’s lift designs, including the New Orleans gondola that was featured on our July cover. We asked Creissels some questions, and share his answers here with our readers. —The Editors
Q. Please explain your role in the ski lift industry. For example, are you retained by a ski resort or by a lift company?
A. For the past 25 years I have been a consultant-engineer specializing in cable transportation for the ski lift industry. Because France has so few new ski resorts, my job has been more in lift engineering than in master planning. I consider myself an architect of cable systems, from conception to finished product and even the operation of lift systems. Although my main customers are ski resorts, I deal with other companies that need cable systems. One exception to this was in 1982-83, when I consulted with a manufacturer, Poma, in creating and developing the Trans Mississippi gondola in New Orleans.
Q. DMC is your new lift development. Please explain it and its advantages. Are there any DMC’s in North America or do you expect any in the near future?
A. DMC stands for Double Mono Cable, which is a new generation of detachable grip aerial lifts that are double monocable rather than bicable or the classic monocable type. (DMC are also my initials. As a responsible engineer I like to sign what I create.)
The main advantages of the DMC are:
1) The possibility of using widely available and safety-proven components of “light” installations, such as chairlifts and gondolas, on major, heavier installations.
2) The complete stability and verticality of a vehicle as it goes over a tower or when it comes into a station. (Because the two cables are horizontal on towers or in stations, the vehicle remains vertical.) This is especially valuable in windy sites. We have operated the DMCs in 50 mph winds and that is not the top limit.
3) The ability to use medium-load cabins (20 to 25 people) with medium time intervals (20 to 30 seconds). I believed these two conditions are necessary to guarantee a delivered capacity of up to 2,000 people per hour. At the present time, 3,000 is the normal DMC capacity on large installations with short intervals, but we have designed some at 4,500 (one a 25-person cabin every 20 seconds) for an urban transportation system.
I have one main patent for the DMC, but there are several additional ones. There were two important technical advances from the installations in Serre Chevalier (1983) and St. Gervais (1984). There will be three more in 1985: two sections in Les 2 Alpes and the conversion of the jigback aerial tram in Flaine, which, incidentally, should be the biggest aerial tramway in the world with 9,900 VTFH. All these DMC’s are designed and manufactured by Poma.
As for the U.S. market for DMC, I do not have an actual project, but I feel that it is time for one. The U.S. resorts are beginning to think “detachable”.
Q. What do you see for the future of uphill transportation at ski resorts worldwide and for North America?
A. In France and in much of Europe, the U.S. ski resorts were the example to follow for 10 or 15 years, because they were highly efficient — unlike the European resorts with many surface lifts and some heavy aerial tramways which didn’t have great capacity. But for some years now, the U.S. ski lift industry — manufacturers and ski resort managers — has been asleep in its chairlifts. In Europe, especially in France, we have been improving efficiency, economy and comfort of our lift equipment with the detachable grip systems.
For the future of uphill transportation I see only monocable types with maximum capacities falling into these categories: 1) no more (or very few) surface lifts; 2) quad chairlifts for short, economical lines with maximum capacities of 2,000 to 2,400 and speeds between 360 and 460 feet per minute, according to the ability of the skiers; 3) quad detachable chairlifts or eight to ten seat gondolas with capacities of 2,500 to 3,000 (according to comfort and price!) for lines up to 4,000 to 5,000 feet long and verticals of 1,200 to 1,500; 4) the use of DMC’s for the biggest installations. 7 Of course, I am speaking of major ski resorts where there are many ski slopes and plenty of skiers. I recall Gaston Cathiard’s (Poma’s president) remark to a ski resort lift buyer: “Sir, if you have enough skiers to fill my gondola, you will do the best business of your lifetime.” From my experience, this is absolutely true.
Q. There seems to be a problem in the ski resort/ski lift interaction that is rather like the one Sisyphus faced with the rock he kept pushing. It’s a circular problem where the solution adds to the problem:
- A. Lift lines are long and the waiting time is a negative. The solution is to increase uphill capacity.
- B. Fast, modern, high-capacity lifts are installed. But in order to keep the ski experience of a high quality, the downhill component must be improved by increasing grooming, widening pistes, etc.
- C. The faster lifts and the improved, and therefore faster, downhill experience decreased circulation time.
- D. The faster lifts and better skiing conditions attract more skiers, but the decreased circulation time means…
Do you consider this a problem and if so, what is the solution? If you build more lifts, is there a maximum — theoretical or practical — lift capacity and skier density?
A. This is a very interesting and fundamental question. In France, we give top priority to maximize the availability of skiing. Our main resorts are called “ski factories,” but I don’t think this is a pejorative because our skiers can ski without queueing at ski lifts and they have a maximum amount of space on the slopes.
In the U.S., I think you have skiers similar to those in France. You also have the same possibilities for ski lift capacities, but you don’t have the same facilities for piste (slope) widths — except at a few resorts such as Mammoth Mountain. The result is that many resorts have a problem of too many skiers. They must either accept more skiers and have the long lift lines or they must limit the number of skiers.
Actually, the problem is never having too many skiers, but rather trying to have more than the neighboring ski area. I think it will be impossible for a resort with only chairlifts and long lift lines to keep customers if nearby resorts have better lifts — even if the ski trails are overcrowded.
As long as all resorts have only chairlifts, there is really no problem. But as soon as a few resorts get new, comfortable and high performance ski lifts, then all resorts must follow. I believe this trend started last year at Keystone and the competition has now begun.
Q. When you approach a project, to what extent do you take into consideration the desires — both conscious and subconscious — of the skiing public?
A. For ski resort developments, the first consideration is the desire of the skiing public. But for lift designing, the main influences are the ski resort managers who know their customers and ski their resorts every day. We design to that customer’s plan. Certainly we have our own ideas, but we are there mainly for technical advice.
Q. What can the Americans and Europeans learn from each other regarding lifts and lift operations?
A. As I mentioned earlier, your fundamental contribution to our business is your notion of efficiency. European resort managers continue to visit the U.S. to study your resort organization and try to bring it home.
Today, maybe Europeans are going to sell some components for skilifts to the American resort industry; but even here, in a short time — maybe months, maybe a few years — the highest performing lift equipment will be in the U.S.
Q. Are there aspects of the B77 Code that you think we should consider modifying? Do you think any of the changes now being considered constitute a compromise with safety?
A. In my opinion, the B77 is, in spirit, a very good code, because it is simple, clear and provides end results, not just the means to get them, as too many European safety codes do. At the same time, many specifications seem out-dated. For instance, the speed limit for detachable grip lifts, the safety factor for cables (track or haul) and the number of passengers in a cabin without an attendant.
In France we have a very strict code, but a very responsive institution in our Ropeway Board with members from the administration as well as private companies. Every month this board examines requests for variances and they are very flexible and efficient so we can now operate detachable quads at 1,000 feet per minute; monocable gondolas with 10-person cabins at 1,000 feet per minute speeds; DMC’s with 25-person cabins at 1,300 feet per minute speeds, without an attendant; and jib-back ropeways without track cable brakes and some with one haul rope.
It is very important that the B77 makes changes to become more flexible. For instance, it would often be stupid to build six-seat gondolas when 10-person cabins are more efficient, less expensive and just as safe. I would advise resort managers in the U.S. to look at the latest new equipment. Go beyond the actual B77 specifications, even if it may take some years to change the regulations.
