Do trains and planes need wheel alignments and wheel balancing?

Joined
Apr 27, 2010
Messages
18,193
Location
Suburban Washington DC
Just pondering the question while taking a train and a plane the other day. I assume the train's wheels are machined perfectly to begin with, and without tires, there wouldn't be significant variation throughout the wheel's life. Not sure about alignment. And on planes, the time rolling on the ground is minuscule over the tire's lifetime, although when it does roll it can be over 100 mph so imbalance would magnified. If they do get balanced, is the equipment and weights similar to automotive?
 
Train wheels come as an assembly. Like this but all one piece. 2 wheels and an axle... |---|

Seems like heavy stuff does not get tires balanced. Maybe the weight keeps the vibration down? We never balanced 18 wheeler tires.
 
Train wheels come as an assembly. Like this but all one piece. 2 wheels and an axle... |---|

Seems like heavy stuff does not get tires balanced. Maybe the weight keeps the vibration down? We never balanced 18 wheeler tires.
When they do my dads 18 wheeler tires they use liquid balance. They said the reason for that is because they have a lot more vibration so the weights would eventually come off. 🙂
 
Train wheels come as an assembly. Like this but all one piece. 2 wheels and an axle... |---|

Seems like heavy stuff does not get tires balanced. Maybe the weight keeps the vibration down? We never balanced 18 wheeler tires.
I have my steer tires balanced and that’s it. The place I use applied stick on weights to the inside of the wheel. Never lost a weight yet.
 
Train wheels come as an assembly. Like this but all one piece. 2 wheels and an axle... |---|

Seems like heavy stuff does not get tires balanced. Maybe the weight keeps the vibration down? We never balanced 18 wheeler tires.

I've balanced them, on busses. Will see if I see a semi parked if I can take a picture of the balance weights.
 
Wouldn't be worth it to balance a tire on a jet as it would go out of balance on the first landing when it scrubs a sizeable amount of rubber off when the tire hits the tarmac.
Right, and pretty random where that tire touches down to smoke off that initial contact patch
 
Train wheels get “trued” when a car is in the car shop getting maintenance/repair.

it’s basically a huge brake lathe
Freight trains returned here after a 30 year absence … amazing how much better the tracks/ties are
got out to look and was tempted to put a nickel on the track (for old times sake) 😷
 
Seems like heavy stuff does not get tires balanced. Maybe the weight keeps the vibration down? We never balanced 18 wheeler tires.
I'd expect the harmonics, based on the diameter of the tires, to peak over 90 MPH and therefore be irrelevant. You also have very heavy axles and unsprung mass to soak this stuff up.

1990s Miatas, on the other extreme, had 14" wheels, tiny tires, lightweight suspension, and stiff bodies and were pretty picky.
 
We do not balance our Gulfstream's main wheels, but we do balance the nose wheels. They are small and rotate quite fast. The crew complains if they are out of balance. As you might imagine, the out of balance condition is not noticed on landing. But on takeoff, where the nose wheels can spin for a time, it can't be ignored. There is no mechanism to stop the nose wheels from spinning. They will spin in the wheel well after retraction.

The mains have 700 PSI of brake pressure applied the instant the gear handle is selected up. So they stop rotating right away.

The mains are very heavy duty tires, about 1.25 inches thick and about 200 pounds each, assembled. The nose tires are on 10 inch rims and are similarly tough, but so small, they can be lifted with one hand. Most nose wheels take no more than an ounce of weight, which bolts on to one of the wheel bolts in place of a washer.

They are balanced statically.

maxresdefault.jpg


Static-400x400.png
 
Last edited:
As for alignments, that's for Cessna's. The Gulfstream has no provisions for wheel alignment. The accuracy of the components is superb. The axles are forged as one piece (for each pair of wheels) and there is no way to adjust anything.

This is our nose axle. The mains are made the same way, of course, much larger.

H9LpjLq.jpg
 
Back
Top