What is a height pole?


A height pole or high pole or hi-pole is a measuring device that is precisely attached to the front of a pilot car vehicle that is used to measure the height of overhead obstructions during the transport of over-dimensional (tall) shipments by oversize trucking companies. North American states and provinces have laws that regulate and mandate when a height pole is required in order to transport over height shipments within their jurisdiction. To be in compliance with these pre-determined requirements trucking companies must determine if the shipment they wish to transport will require a height pole pilot car or a lead escort vehicle with a height pole installed before applying for a oversize trucking permit.

pilot car truck equipped with a height pole.

Pilot car with height pole attached.

The photograph illustrated here is a typical example of what a pilot car vehicle might appear like when equipped with a height pole.  You can clearly see the measuring device affixed to the front of the vehicle as it is very tall. A height pole is typically made out of sections of fiberglass that are adjustable to meet the requirements by each state/province the shipment will be transported through. Typically the height pole will be adjusted to a height that is 6 inches (or 15.24 centimeters) taller than the shipment is when loaded onto the shipping trailer. Then once the actual transport of the item takes place the pilot car equipped with the height pole will proceed in front of the over-dimensional (tall) load being transported. If a driver of the pilot car equipped with the height pole (hi-pole or high pole) hears the fiberglass height pole hit any obstructions in the path of the shipment the operator will then immediately notify the driver of the truck transporting the shipment informing of the obstruction in order to prevent any damages to the shipment or the obstruction. When a height pole is properly mounted to the escort vehicle it is connected to the frame. If the height pole does happen to strike any objects the sound heard by the pilot car is very loud and distinct thus alerting the driver of the obstruction. It has been noted as recently as 2015 in excess of 169 million dollars in overhead obstruction damages were caused during that single year in the United States alone. So having these safety measures in place is most definitely in the best interest of everyone from the tax payer, to the safety of the motorists and the owner of the shipment being transported as well as the transportation company.

The importance of installing a height pole correctly.

There’s no such thing as cutting corners when installing a height pole on your pilot car. It’s extremely important it’s directly connected to the frame of your pilot car for two reasons:

  • Ensure it is sturdy, stable and not going to fall off of your vehicle.
  • So you can hear the sound it makes if it hits any obstruction. To do so properly it must be attached to the frame.

In order for the pilot car vehicle operator to properly hear the sound created by the height pole if a obstruction is hit it is imperative the device be properly and securely mounted to the vehicle in such a manner the bracket holding it is connected to the frame of the pilot car vehicle. In order to obtain the absolute highest quality from installing this device you may wish to make certain you are not adding sub-supports for your height pole when designing your attachment method.

Suggested methods of attaching a height pole.

While there are many different way to install a height pole on your pilot car vehicle we strongly suggest you locate a heavy-duty bumper grill made from heavy tubing such as you might see on law enforcement vehicles. If you are able to locate a front bumper/grill protector attachment you then have a few options:

  • The first would be to cut the top portion of the bumper guard off so your height pole can easily slide in/out of the pole. Make certain you devise a method than locks it in no matter how you decide to attach it.
  • The second option would be to locate a small piece of pipe the base of the height pole snugly fits into and weld this onto the bumper grill attachment.

This will require some planning, designing and fabricating on your part in order to weld the pipe in place so it stands perfectly vertical but well worth it if you wish to work with shipments that are over-height.

The bumper grill works so well due to the fact it usually connects with two bolts to your vehicle. The tubing these are constructed out of is not only heavy-duty but very close if not the same as the base of most height poles. So not only do it properly but efficiently as well.

Why is it so important to connect high poles to the frame of pilot car vehicles?

A good quality sound must be made if any obstructions are hit with the pole. You want to consider all of the other noises that occur when you are operating your pilot car vehicle. You’ve got the sound of your engine, the sound of your tires on the road as well as any 2-way radio chatter. Other sounds such as sirens, trains, air-planes etc. are frequent as well. Because the height pole is so important make sure if it does strike something overhead it clearly makes a loud sound. This will  instantly alert the operator by being indistinguishable from any other sounds or background noises.


What is a double drop trailer?

What is a double drop trailer?

If you are wondering what a double drop trailer is we may be able to help you learn all about them. Double drop trailers (sometimes referred to as a lowboy or RGN) is a specialized trailer that has many very unique capabilities. The deck design on double-drop trailers is very unique meaning primarily it is low to the ground and specifically meant to service the oversize and overweight (heavy-haul) trucking industry. One of the advantages of double drop trailers is they are capable of shipping items that are excessive in height that otherwise may require a special oversize trucking permit in order to be transported. This means transportation costs will be higher in order to successfully ship the item. However, thanks to the double-drop trailer transporting machinery and items that are excessive in height is cheaper to perform. In this review we’ll  cover double-drop trailer dimensions, axle spacings, axle groups, weights, accessories and much more so let’s check it out in detail!

standard double drop trailers.

Learning double drop basics.

Always be sure you clearly understand all of the state(s) laws, regulations, rules and limitations prior to shipping any type of load on a double drop trailer. Regulations in each state differ and you should fully research them prior to moving any load to make sure you are in compliance. Oversize and heavy-haul loads require specialized trucking permits in order to be transported. Always refer to your actual state issued permit for any discrepancies you may have. Be smart, be safe and know exactly what you are doing before doing it.

Note: It should be clear that any weights or dimensions listed below are for the purposes of example only so you are able to learn about double drop trailers.

Empty weight: refers to the actual weight of the semi-truck and the double drop trailer.

Item weight: refers to the actual weight of the item being shipped. Generally speaking a double-drop trailer can ship from 41,000 to 43,000 pounds maximum legally without being required to obtain a heavy-haul trucking permit.
Over-all weight: refers to the weight of everything combined. The semi-truck, the double drop trailer and the item loaded onto the trailer. The gross maximum weight of any combination of trailer, semi-truck and item being transported must not exceed 80,000 pounds (GVW) of the shipment will be required to obtain a heavy-haul trucking permit from each state the item will be transported in. When very heavy items are being shipped extra axles are required to spread the weight of the item over a larger distance so its foot print on the road is still the same as a legal shipment that is under 80,000 pounds. The exception to this general rule is bridges. All heavy-haul shipments that are transported over bridges must comply to federal bridge formula to ensure safety.
Heavy-haul loads: When a load exceeds the overall maximum allowed weight or axle group weight limits set fourth by the states regulations a special heavy-haul (overweight) trucking permit is required to be purchased from the state it will be transported in. Heavy-haul trucking permits usually cost more than a basic oversize trucking permit.

Accessories used with double drop trailers.

Quite a few double drop trailer accessories are available in order to make loading/unloading easier as well as protecting the item that is being transported. In many cases the owner of the double drop trailer may add ramps to the trailer thus making it easier and quicker to load/unload items. Especially farming equipment or dozers, loaders, back-hoes and scrapers or any specialized equipment that has tracks or wheels. One of the most popular accessories is traps. Tarps provide protection for items that are being shipped and can cut down on the possibility of damages. Keeping insurance claims to a minimum is always a smart idea.

Double-drop trailers with additional axles.

Heavy equipment shipping is a demand that is increasing. As we grow so do our capabilities which usually means larger equipment. As you can see in our illustration above 5 axle double-drop trailers are in demand these days and the owner of one with the right customers can have a 5 axle double drop combination running team drivers pretty much year round.

​Large equipment hauling on double-drop trailers.

​Flatbed oriented trailers are capable of hauling a very diverse range of items. While items like connex trailers, tiny houses and general freight can help keep a trucking company rolling on the road with generating revenue the real purpose of double-drop trailers is hauling big and heavy machinery and equipment. As we mentioned earlier the target market for double-drops is equipment and machinery that may be heavy but tall is the key element that allows this trailer type to be so diverse.