Has anyone ever driven a truck with twin steer axles?

Let's hope he was just having a bad day. As a former tow company owner I would not let just any driver operate a truck like that. Usually the big rotators and heavy wreckers are earned by the best at the company.

As for driving them, the twin steer turns as well if not better than a single steer axle.

 

It was actually pretty nice. Drove, shifted and everything felt just like a semi or straight truck. The biggest difference is being about 80k in a single unit vs like a tractor trailer. Idk kind of hard to explain.

 

Still seems like an odd set-up. Placing that 4th axle farther back (placing 23K on a single steer) would have lessened the overweight situation on the drives. Granted, it would still be at least 9800# over-gross, but by running a 23K steer axle at 3K over the 20K limit, the tri-drives (allowed 45K if over 10') would only be 51,800...or 6800# over. That would also give enough "extra" on the mfg specs of the axles, tires, and suspension to allow for a truck to be towed without over-stressing components. As it is, no typical truck tire is going to be rated heavy enough to use on the drives if they are actually towing anything...pushing it just running down the road empty. That's another reason why, whether recognized or not, it was bordering on silly specing it with just a tandem drive. It also limits who will be willing to buy it if/when it needs to be sold. Nobody from a state that DOES recognize the extra axles (and will require them) will be interested in a truck that doesn't have the axles to be legal.

But, it ain't my money that bought it, and I'm not the one risking the overweight citations every time it hits the road...so my opinions really don't matter. Sometimes I wonder what it'd be like to have more money than brains...but in the end, I'm glad that's a problem I don't have.

 

My guess would be the chance of the main wrecker at an incident getting an overweight ticket is nill.......

 

You don't have to worry about over weight citations, as they sit they need a blanket weight permit just to drive empty. Anything over 65k as a straight truck does in all but a handful of states. Violates Federal bridge laws. Now, once loaded they are typically exempted from axle weights thanks to a change in the FAST Act a few years back.

As for tires, they run 11R24.5, so it is a bit over on the tires. Not much, the axles are spec'd for 54k (have a slight spead to them) and when you do the math for picking a disabled truck you add about 9 or 10k to the tandems is all. As you know from when you towed, leverage is your friend and the rear axles simply act as the fulcrum in the lever.

The other reasons for tandem drives are tow capacity -the capacity is based on a wheel base and overhang formula, having a tridem gives you more overhang and reduces the amount you can lift with the underlift (the more overhang beyond the center of the drive the lower lift capacity due to steer axle unloading).

Also, and this is Jerr-Dan specific, the way their rotator platform is designed does not allow for a tridem axle spacing. They have the most stable outrigger platform on the market but the trade off was frame space for traditional axle spacing. These trucks lift like a beast, our 60 T out lifts the Miller 75 T at the same boom extension, especially off the rear corner where rotators are weakest.

Now, for those that are not really concerned about weight distribution we also offer a single steer version of this truck with a steerable lift axle between the outriggers. They drive a bit squirrely when not towing but some guys want them.

 

You would be suprised. Before the Fast Act changes a few years back several states were notorious for doing DOT inspections on tow trucks while enroute or at crash scenes. Pennsylvania was one of them, have had my trucks inspected while cleaning up a wreck that had I-84 closed!

 

Awhile back we had a heated exchange on another thread.... The question was, is a rotator more versatile/better than a 50/70 ton hyd crane at an incident scene ?

What do you think .....

 

Depends on what needs to be done. The biggest difference between a rotator and a traditional crane is the ability to lift and drag vs. just straight lift.

A crane excels at straight lift and swing work, they usually have much more hook height and a longer boom so they can lift further away from solid ground than a rotator can.

A rotator can winch the casualty into place, lift and winch it closer as needed, as well as swing the load. That said, most rotators have between 37 and 42 foot maximum hook height, add in rigging below the hook and you have limitations on how high you can lift a casualty to clear ground obstructions.

Now, in the towing and roadside incident management world we try to only lift as high as absolutely necessary, usually no more than 4' (high enough to load on a trailer).

Rotators also excel in this field for rescue operations as there are no counterweights to install, quick setup and you are ready to lift. That is why many metro fire departments have them in their technical rescue fleets. LAFD has two, maybe three 75 ton rotators, Miami Dade has a 60 ton Jerr-Dan.

Here in North America the rotator is the gold standard for incident management on highways, whereas overseas knuckleboom cranes are the standard. Australia seems to lean towards more truck mounted hydraulic cranes with a few American made rotators as well.

Most of the world uses knucklebooms, don't know why they have not caught on here in the US.