PIKE LAKE AND EASTERN

HARTFORD SHOPS


STANDARD 14


LOAD CALCULATIONS


REVISED 06/01/03



The following calculations sizes the drive system for a locomotive.


A) ______ lbs Operating weight of engine


B) ______ lbs Total weight of cars


C) ______ lbs Total weight of passengers


D) ______ % % of steepest grade


E) ______ ft Radius of sharpest curves on grade


F) ______ lbs Total train weight = A + B + C


G) ______ lbs Rolling resistance = F x .006


H) ______ lbs Curve resistance if E = 35 ft to 45 ft H = F x .008

if E = 45 ft to 60 ft H = F x .006

if E = 60 ft to 90 ft H = F x .005

if E greater than 90 ft H = F x .003


I) ______ lbs Grade resistance = D x F x .01


J) ______ lbs Total train resistance = G + H + I (tractive effort required)

we ignore wind resistance and accretion


K) ______ Coefficient of friction – wheel on rail, range 0.1 to 0.3

we assume 0.25 for dry rail, 0.1 for wet rail


L) ______ lbs Weight on powered drivers


CHECK L x K must be greater than J


M) ______ in. Drive wheel diameter


N) ______ in Drive wheel circumference = M x 3.1416


P) ______ MPH Desired travel speed


Q) ______ in/min Travel speed in inches per minute = P x 1056


R) ______ RPM Wheel rpm = Q / N


S) ______ lb-in Total axle torque required = (M / 2) x J


T) ______ HP Total hp required at wheels = ( S x R) / 63025







STANDARD 15


STEAM LOCOMOTIVE CALCULATIONS


REVISED 06/01/03



The following calculations sizes the drive system and boiler for a locomotive.


A) ______ lbs Weight on drivers (standard 14 L )


B) ______ lbs Drive wheel diamater (standard 14 M )


C) ______ MPH Desired travel speed ( standard 14 P )


D) ______ lb-in Axle torque required ( standard 14 S )


E) ______ lbs Tractive effort required (standard 14 J )


F) ______ in Cylinder stroke 2 x crank pin radius


G) ______ in Cylinder bore (enter if known otherwise calculate)


H) ______ PSI Boiler pressure


I) ______ in Drive wheel circumference = B x 3.1416


J) ______ in/min Travel speed in inches per minutes = C x 1056


K) ______ RPM wheel rpm = J / I


L) ______ HP HP required at wheels = (D x K ) / 63025

M) ______ PSI Mean Effective Pressure (MEP)

IF 85% cutoff = .98 x H

80% cutoff = .97 x H

75% cutoff = .96 x H

60% cutoff = .88 x H


N) ______ PSI Average cylinder pressure = M x efficiency

efficiency = 75% (losses in boiler piping)



P) _____ in Calculated cylinder diameter



CHECK G must be larger then P



Q) ______in/min Piston speed = K x F x 2


CHECK Q should be less than 3600 in/min



Boiler

R) ______ sq in Grate area = E / 3.5


S) ______ sq in Tube area = R / 8


T) ______ sq in Stack area = R x .06


U) ______ in Nozzle area = R x .005