Undercarriage gates are a popular option for cantilever sliding gates of many sizes. The early versions of undercarriage gates did experience problems. The way it works is that an inverted wheel set of usually four or two wheels is then surrounded by a C channel metal section which is welded to the base of the gate.
One of the issues with this technique was that early on, the C channel over time tended to open up. This meant that the gate started to move within the channel which led to mechanical issues such as the gate dropping from its original installed position in the closed position. This then leads to ongoing issues with the drive mechanism such as the gate racking and connection point with the motor cog. Most if not all of these issues have been resolved in recent years now making undercarriage gates a more viable option than ever before.
Leda is one of Australia’s largest manufacturers of cantilever gates. Now undercarriage gates are sold on gates with widths of 3 to 4 meters right up to 13 meters in width. Most recently we have seen overseas cantilever gates of up to 30 meters in width for special applications. The point is that previous restrictions on gate width are largely no longer an issue.
The undercarriage gate is a traditionally popular model in both North America and Europe as it has the distinct advantage of not being encumbered by snow and ice like traditional Australian designs which have a runner beam section next to the gate which secures the back of the gate leaf at all times.
This design would not work in an environment subject to snow and ice on a regular basis. So while there are some material savings with the undercarriage system, the undercarriage system itself does carry more costs. The eventual cost outcome is about the same for either a traditional or undercarriage system so I would recommend to any customer looking at either system to make a decision based on the merits of the gate other than cost. Because the undercarriage system effectively has four rollers from the sending post and another four rollers further back to counteract the cantilever effect of the gate being suspended, there is very little ‘point’ loading which is a major advantage.
What I mean by this is that on a traditional gate there is one roller at the sending post for which all the weight of the gate is then suspended on. The undercarriage system is able to better dissipate the weight and by simply adding a second roller (if not four) the point load from a one roller system is either half or more. This makes the gate far easier to open and close manually.
Where power outages or emergency requirements may require a large or heavy gate to be opened manually then the undercarriage system should be considered as generally it will be an easier system requiring less force to open and close. Additionally, the gate in not requiring a runner to hold the rear of the gate so takes up less room in the location where the gate retracts to.
So in effect the gate requires less of a footprint from traditional cantilever gates. This was very apparent on a number of wharfs where Leda were able to install an undercarriage system on a wharf suspended over water. The gate in the open position is able to be suspended far out over the water which is impossible with a traditional cantilever gate.
Lastly, not all undercarriage systems are created equal. A number of cheap knockoffs are available from a number of suppliers which can lead to ongoing issues with undercarriage gates if not done properly. The gates are slightly more technical when supplied as undercarriage gates and it is important that purchasers understand the pros and cons of this system and the manufacturers they are charging with making the gates to an acceptable standard.
Longevity as with any product is important and Leda has been manufacturing gates for almost 20 years and is best able to assist with your gate design.