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Jul 18, 2018, 5:37 am

#76

Globaliser

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Join Date: Aug 2002

Location: London

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Quote:

Originally Posted by MPH1980

So given the tug is only lifting at the point of the front wheel - surely it only needs to be able to handle a 3rd of the weight?

Given where the aircraft's centre of gravity/mass is, I wonder whether the nose wheel bears anything near one-third of the aircraft's weight.

Jul 18, 2018, 5:41 am

#77

T8191

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Quote:

Originally Posted by Globaliser

Given where the aircraft's centre of gravity/mass is, I wonder whether the nose wheel bears anything near one-third of the aircraft's weight.

Possibly as little as 5%-10%. Where's waterhorse?

Jul 18, 2018, 5:51 am

#78

Calum

Join Date: Jul 2014

Location: Edi

Posts: 2,203

Quote:

Originally Posted by MPH1980

I'm possibly being very silly here - but there's 3 weight distribution points on the planes - front wheel and two wheels under the wing.

So given the tug is only lifting at the point of the front wheel - surely it only needs to be able to handle a 3rd of the weight?

Ah you may have hit the nail on the head... I assumed that because the smaller one (The one in use at T5A) is rated for 90T (Slightly more than the MTOW of a A320), that it was based on the aircraft weight.

Should of done physics in school..

Jul 18, 2018, 6:12 am

#79

Deltus

Join Date: Oct 2015

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Quote:

Originally Posted by Calum

Should of done physics in school..

Arguably you should have done English too...

corporate-wage-slave, T8191, TrainDriverSparky and 4 others like this.

Jul 18, 2018, 6:13 am

#80

babats

Join Date: Aug 2009

Location: North of Watford Gap

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Quote:

Originally Posted by MPH1980

Larger planes like the B747 & A380 have 5 sets of wheels so even less of a problem moving these.

Jul 18, 2018, 8:07 am

#81

Calum

Join Date: Jul 2014

Location: Edi

Posts: 2,203

Quote:

Originally Posted by Deltus

Arguably you should have done English too...

U wot m8?

Jul 18, 2018, 10:52 am

#82

MPH1980

Join Date: Aug 2012

Posts: 2,676

Quote:

Originally Posted by babats

Larger planes like the B747 & A380 have 5 sets of wheels so even less of a problem moving these.

Except - of course - the friction generated by the increased surface area of the wheels will be greater and the overall mass you have to move is still huge.

I'd guess the makers of this machine have two concerns:

1) can the lift actually lift the wheel
2) can the drive produce enough force to move the whole aircraft.

Both of which are problems which have already been overcome with the petrol driven tugs ... so presumably it's more a question of doing it in a compact, battery driven, situation.

Jul 18, 2018, 12:09 pm

#83

Forever in Seattle

Join Date: Mar 2015

Programs: BA Gold

Posts: 689

Quote:

Originally Posted by MPH1980

To push these planes they have to have a loads of ballast to get traction. The ones BA uses are Douglas DC-12's which weigh 50 tonnes themselves (Older conventional tugs, which are probably kicking around in use), or towbarless TBL-400/600's which weigh 30/37 tonnes each, and all have some big diesel engine in them.

Fun fact, the Armored Personal Carrier in the 1986 movie Aliens, was an ex British Airways tug (Hunslet ATT77).