Different Types of Cable Transport Explained

Types of Cable Transport
Image credit: Holmatro via Wikimedia

Different scenarios call for different types of cable transport. While they all feature cable cars, cables, and mechanical systems, the implementation differs.

Different types of cable transport systems bring functionalities that best suit specific scenarios. While we could use the same design for ski resorts on streets, improving efficiency in both cases won’t hurt.

With that in mind, you can see why cable cars over valleys require a different design than those for streets. We will look at the various types of cable transport and explore where the designs work best. So, without further ado, let us get rolling.

Typical Components of the Different Types of Cable Transport

While we could jump straight into listing the types of cable cars, you might miss the bigger picture. That is because these systems share similarities, regardless of their different implementations.

So, what do the different types of cable transport have in common? They share several components. These parts essentially define the entire build of the system, and cable cars would not exist without them.

In addressing the parts, we will look at different sections of the transport media. Let us begin with the propulsions.

Propulsion

Cable cars do not have onboard engines or propulsion systems. You cannot find an internal combustion engine or an electric powertrain on them. How, then, do they move?

A massive propulsion system, located at one end, pulls the cables continuously. It could be a steam engine, an international combustion system, or an electric powertrain.

Regardless of choice, it must be powerful enough to pull a fully loaded cable car without hassles. Newer propulsion systems, of course, create fewer emissions, resulting in less environmental pollution.

The cable cars use a grip to latch onto the cables and glide along pre-determined tracks. They have guard rails that keep them from derailing.

Grips

Cable cars must grip the cable for the motion to occur. Without this crucial component, they cannot move from one point to another.

Grips operate through a lever and require manual actuation from the gripman. Newer systems feature electronic controls for effortless and more efficient operations.

Grips are the primary differentiators among different types of cable transport. We will see more on them in a bit.

Towers

While some cable transport systems require towers, others don’t, at least to a certain degree. Towers are crucial to maintaining the needed cable tension. Without them, we will have sagging ropes, which may result in accidents.

More enormous towers have greater distances between them, unlike the smaller ones. Nevertheless, the size depends on the cable technology and system capacity.

Different types of cable transport require unique tower designs. Once the designers understand the requirements of the cable transport system, they can design the towers for more efficient operation.

Support

Supports are crucial, and different types of cable transport have unique implementations. These systems provide the guideway along which the cable cars travel.

In some cable transport systems, they carry the weight of the cars. Such functionality requires robust support, especially when dealing with a fully loaded vehicle.

The Two Major Types of Cable Transport

We briefly introduced the components, so you will better understand the types of cable transport. Despite several variations, there are only two major types, viz:

  • Top supported
  • Bottom supported

While those mentioned above are the major types, we will find some sub-divisions within them. That is due to the different applications and requirements.

In other cases, you might see the following classification:

  • Aerial transport
  • Cable railway

They both point to the same thing as regards the support system. Let’s begin with the top supported system, regardless of the different nomenclature.

Top Supported Cable Transport

Without much explanation, a simple sketch would show support from the top. The cars run along the length of the cable in a suspended way.

This system requires towers along the cable lengths to keep the needed tension and prevent sagging. The latter is dangerous, especially in weighty situations.

As mentioned earlier, towers have different sizes, depending on the length of the cable and the weight of the cars. Asides from the strength of the cables, the towers must be strong enough to carry the weight of the cars without buckling.

As a simple description, that would mean bending over. Take the simple robe line you use to dry clothes, for instance. You will notice the sagging as the weight of the combined clothes increases.

However, pay attention to the poles supporting the robe. The bars tend to bend inward in the event of a lightweight rod and heavy laundry.

Such a simple demonstration also applies to the top supported type of cable transport. It works through the use of towers.

The top supported types of cable transport have seen extensive application in mountainous regions. In such places, constructing roads or other means of transportation is often tricky.

As a result, cable transport has become the most feasible. Another area where you will most likely find this system is mining. The ease of moving and installation has made it the method of choice in mines and crossing rivers/ravines.

Also, it permeates intra-city transport, as we are currently witnessing the use of the gondola lift in urban public commutes. With that in mind, let us explore the top supported types of cable transport. They are as follows:

Aerial Tram

An easy way to differentiate an aerial tram from other types of cable transport is the number of cables. This type uses three cables: two for support and the third for propulsion.

The aerial tram has a permanently fixed grip. A famous example is the New York Roosevelt Island Tramway.

Gondola Lift

The gondola lift has one continuously moving cable that spans two or more stations. Of course, there will be support towers in-between the stations.

A primary bullwheel in the terminal drives the cable, with support from an internal combustion engine or electric motor. Detachable grips are the primary mechanisms, enabling the gondola cabins to slow down at the stations for boarding.

Nevertheless, fixed grip variants are still in play, though they are less common. The gondola lift is versatile among the different types of cable transport systems.

Designers can vary different aspects to accommodate more capacity or functionality. You will find the gondola lift in urban transport, some with one support robe and one haul robe.

Funitel

The Funitel is more of a variation of the gondola. It uses two overhead arms that grip two parallel haul cables, which gives it more stability, especially when high winds come.

Further variations of the Funitel are the double monocable (DMC) and the double loop monocable (DLM). The former uses two haul cables, unlike the latter, which uses one round-looped haul cable.

Funitels can be versatile, but the absence of seats makes long trips uncomfortable. Also, skiers must remove their skis or snowboards before stepping aboard.

Although we can say the same about large gondolas, funitels have a slight advantage. The use of two cables means additional strength to carry more weight.

As a result, the capacity per cabin usually ranges from 20 to 30 passengers. Funitels often go for short trips while passengers change cabins.

Funifor

The funifor uses three ropes but differs from other types of cable transport in looping. Two ropes provide the support, while the third hauls the cable car—however, the propelling cable loops around to the bottom.

Unlike other systems where the cable loops serve other tracks, the Funifor robe serves only one track. One benefit of this design is allowing single cabin operations during low-traffic hours. There is no need to run the other cabins if there are not many passengers.

The funifor allows for easy evacuation in the event of an accident. Rescuers can effortlessly set up a bridge between the cabins to evacuate the stranded passengers.

Notwithstanding, the funifor shines among other types of cable transport because of its high wind stability. The two support ropes have ample horizontal distance to provide stability.

Designers have played around with the Funifor. We have installations with two parallel and independent lines.

Hölzl, the Italian manufacturer, developed the Funifor. However, a merger with Doppelmayr Italia gives the patent credit to Doppelmayr Garaventa Group.

Chair Lifts

Chair lifts have the most significant advantage of allowing skiers to board without removing their gear. As a result, they are the most common in ski resorts and mountainous regions.

Of course, let us not forget to mention the amusement parks. A simple description of chair lifts would be a set of chairs in continuous circulation.

Chair lifts are of two types; fixed grips and detachable. The latter can reach speeds of 5 m/s, unlike the former, which averages two m/s. However, the speeds of detachable chair lifts are faster than the safe disembarking speeds.

The design connects each chair to a cable using a powerful spring-loaded grip to fix that. This cable grip detaches when the chair reaches the terminals, allowing for convenient onboarding and unloading of passengers.

For added protection against harsh weather like snow storms, chairs may have a bubble canopy. Chair lifts play a crucial role in the types of cable transport.

Bottom Support Cable Transport

The bottom support system has extensive usage on steep slopes, where gravity plays a significant role. When the slope is too steep for other forms of transport, it becomes the best alternative.

A prominent example of this type of cable transport is the funicular. The passenger railway cars, which are isolated, have a permanent attachment to the cable.

Nevertheless, there are other designs where the cars have temporary attachments to the cables. They often detach at the end of the line.

Also, the bottom support system does not necessarily require a steep slope. In processing plants, you could find such cases where the cars move between the plants and the quarries. With that in mind, let us see some bottom support types of cable transport.

Stationary Engine

The California Cable Car is a clear example of a stationary engine. It moves due to propulsion from a central power system.

Hence, a stationary engine, centrally located, drives the cars through the travel distance. It may also slow down loads going down a slope.

Often, this bottom-supported system has only one track and cable. The engine could be an internal combustion engine, a steam system, or a water wheel.

Gravity Balance

The prominent feature that sets this system apart from other types of cable transport is the absence of a central engine. Instead, the movement relies on the force of gravity.

You still have ascending and descending trains in the gravity balance system. However, the descending train drives the ascending one. It is a simple design that removes the need for an engine.

The descending train, often loaded, pulls the ascending train. For smooth movements, the ascending one is often empty to reduce the power needed to move it up the slope.

You can tell the two opposing trains or cars use one cable, as it is the only way for the descending one to pull the other. This system might cost less to operate, but it is inefficient in cases where you need to move goods up the slope.

Water Balance

The water balance is a variation of the gravity balance that allows the upward movement of goods. To achieve that, it uses a water tank that increases the weight of the descending train.

The combined weight of the tank and the train creates enough force to pull the ascending train up the slope. You can either have the water in the descending wagon or under a trwnc car that carries the empty train.

A prominent example is the Aberllefenni Slate Quarry. Although the water balance has the added advantage of carrying goods uphill, it has a significant downside.

You must have a good supply of water to implement this system anywhere. Besides, it would be impractical to use it to move goods uphill. You are better off trying other types of cable transport if water will pose a challenge.

Locomotive-Propelled

How about a system that propels itself rather than using a central engine? That is what locomotive-propelled cable transport does.

It ditches the use of a central engine. Instead, we have a locomotive with a winding drum that powers the cable for motion.

As a result, the car climbs the hill through the winding of the cable. At full length or the summit, the operators rewind the cable after fastening the locomotive to the rails.

Hybrid Cable Systems

We cannot wrap up the types of cable transport without mentioning the hybrid systems. Although few, this type assists conventional trains in climbing steep slopes.

In hybrid cable railways, the trains’ self-propelled systems are often not powerful enough on a steep slope. To fix that, a stationary engine drives a continuous cable.

The train latches on to this moving cable to ascend the slope without much strain on its in-house engine. It is a straightforward implementation that saves costs and lengthens the lives of the trains.

The Cowlairs incline and the Erkrath-Hochdahl Railway in Germany are famous examples of the hybrid system. However, these examples are now relics of the past.

Conclusion

The search for more efficient movement of goods and passengers led to the development of different types of cable transport. Although efficient, they are yet to see widespread adoption in intra-city commutes globally.

The top-supported system works best in mountainous regions. It uses one driving cable, even with several variations. Among them, the gondolas have seen the most adoption in the cities to move goods and passengers.

Whether cable transport systems will replace buses and trains is yet to be seen. Nevertheless, we can expect more development in the coming years.

Cable transport is far from its peak in innovation. While there might not be many design changes, the propulsion mechanisms might see changes. In the end, we will have more efficient systems in our cities.

Total
3
Shares
Leave a Reply

Your email address will not be published. Required fields are marked *