For an electric locomotive or a diesel-electric locomotive, starting tractive effort can be calculated from
the amount of weight on the driving wheels
(which may be less than the total locomotive weight in some cases), combined stall torque of the traction motors, the gear ratio between the traction motors and axles, …
What is total tractive effort?
Total Tractive Effort is
the net horizontal force applied by the drive wheels to the ground
. … This quantity does not change with the number of drive wheels. The sum of the individual drive motor torques (see Motor Specifications) must be greater than or equal to the computed Wheel Torque.
What is tractive effort of a train?
Tractive effort is
the force required to haul a load
. Tractive effort, when multiplied with speed at which the train is required to run, gives the HorsePower.
How do you calculate HP from tractive effort?
HP by definition is equal to
Tractive Effort (TE) x Speed divided by 550 lb-ft per second
.
What is the formula for tractive effort?
For an electric locomotive or a diesel-electric locomotive, starting tractive effort can be calculated from the
amount of weight on the driving wheels
(which may be less than the total locomotive weight in some cases), combined stall torque of the traction motors, the gear ratio between the traction motors and axles, …
Why is tractive effort needed?
Cars in a curve require a good deal of tractive effort
because the wheels are mounted on solid axles
. Thus the wheels must slip and slide through the curve because of the difference in radius of the inside and outside rails. Wheel flange contact adds additional friction.
How do you find maximum tractive effort?
The maximum tractive torque (MTT) a wheel can transmit is
equal to the normal load times the friction coefficient between the wheel and the ground times the radius of the drive wheel
. Interpreting Results: Total Tractive Effort is the net horizontal force applied by the drive wheels to the ground.
What is maximum tractive effort?
Maximum tractive effort: Maximum tractive effort is defined as
the highest tractive force that can be generated under any condition that is not injurious to the vehicle or machine
. In most cases, maximum tractive effort is developed at low speed and may be the same as the starting tractive effort.
What is the difference between traction and tractive effort?
The force available at the contact between the drive wheel tyres and road
is known as ‘tractive effort’. The ability of the drive wheels to transmit this effort without slipping is known as ‘traction’.
What is meant by tractive resistance?
The resistance to motion due to friction per unit weight hauled
.
What is maximum drawbar pull?
DRAWBAR PULL, MAXIMUM:
The maximum towing force in pounds or Newtons at a specified coupler height that a truck will develop on a level surface
.
How fast can a locomotive accelerate?
The final factor and one frequently overlooked is the tractive effort required for acceleration of the train. It takes about 10 pounds per ton to accelerate to a speed of 6 miles per hour in one minute or
12 miles per hour in two minutes
, a reasonable rate for a heavy train.
What is meant by tractive force?
:
the force in pounds exerted by powered equipment (as a locomotive) as measured for statistical purposes at the rim of the driving wheels
.
What is tractive effort and tractive resistance?
When tractive effort TE is equal to the tractive resistance TR a vehicle would be either stationary or moving at a uniform velocity. It the tractive effort
exceeds the resistance the
vehicle will accelerate until the tractive effort once again equals the tractive resistance.
Which factors limit the maximum tractive effort in vehicles?
The limiting friction of the tyre
is totally different. It is peak shear force divided by the imposed vertical force. The limiting friction of the tyre determines the maximum tractive force that the tyre can produce, and is entirely independent of the rolling resistance.
Is tractive effort a torque?
The tractive effort is obtained by
multiplying the torque by the total ratio of power train
and dividing this sum by the rolling radius of the driving tyres.
