When it comes to under-gate Jack operators, these generally control the gate by directly moving the pivot point of each gate leaf. This makes the unit cosmetically ideal while this also allows for up to 180 degrees of leaf swing as needed. The thing to note is that controlling the pivot point of the gate is just like you are opening a door by twisting the hinge. That is why it becomes very difficult because of the loads required at that moment.
This is highlighted with snap since the gate has to be changed directly, as soon as possible. That is why these seem to be only suitable for the ‘Domestic’ systems or in a low abuse environment. Another crucial thing to consider regarding the use of under-gate units is the water immersion/ingress and the warranty voidance. When the water table is high or if the drainage of the foundation box of the unit is inadequate throughout the systems life, then the chance of water ingress as well as unit failure is increased.
Generally, ram or link arm units are simpler to set up and maintain. These are visible to ignorant abuse. Also, since they are fixed down along each gate leaf, they come with an apparent and major, mechanical advantage over the Jacks. That means Rams are way more suitable for the Multi-user & commercial systems. Also, the manual release is always above ground which often makes it more user friendly in terms of operation.