BOStrab Guidance Regulations (Technishe Regeln Spurführung - TR Sp)
Appendix 2
Page 1 of 8
Appendix 2
Construction of the transverse measurement proof
The construction of the transverse measurement gives all values relevant for a safe wheel:rail
relationship and where appropriate its wear limits:
1.
Wheel - wheelset - wheel pair
New measurements with fabrication tolerances as well as wear limit measurements for:
- Wheelset back to back distance r
- Flange width e and/or Flange thickness d
- associated flange back face relief f
- Flange height h
Derived values:
- Wheelset gauge s
- Check Gauge l
- associated flange thickness d
additionally:
-wheel width b
- Flange root radius
-Gauge face profile
-Front bevel (if available)
-Distance between the wheel contact points m
-Vertical distance of the wheelset gauging plane from the wheel-rail contact point a
as well as new and fully worn limit values for:
- Wheel diameter dM
- Slope of the flange front and back flanks 1:nS and 1:nR
- Radii of the outer and inner flange tip rounding rK,S and rK,R
The wheel profile dimensions are to be considered in the new and fully worn states.
2.
Track, turnouts & crossings
Originally drafted: March 2004 Issued (in German): May 2006
Translated from the German for UK use January 2009
BOStrab Guidance Regulations (Technishe Regeln Spurführung - TR Sp)
Appendix 2
Page 2 of 8
2.1
Determination of the values for the transverse measurement table
The gauge and flangeway (and where appropriate check gauges) are set out in tabular form
according to the track curve radius for plain track, turnouts and crossings, with building
and/or fabrication tolerances as well as relevant safety limits. The vertical distance A
between the gauging plane and the GFT is to be indicated.
The different types of turnouts and crossings are differentiated by –
- those with a simple crossing and check rails
-
where the crossing lies on the outer rail of a curved track (simple turnouts,
opposite curved turnouts, inside leg of curved turnouts)
-
where the crossing lies on the inside rail of a curved track (outside leg of
curved turnouts)
- those with double crossings
In addition, crossings are differentiated according to:-
those with deep groove flangeways through both the crossing and check rails
(and where necessary, between block and rail built crossings)
-
those with deep groove flangeways through the check rail (inside rail of curved
track) and flat grooves through the crossing
-
those with flat groove flangeways through both the crossing and check rails
The use of deep groove crossings is, in the fully worn condition, dependent
on the smallest allowable wheel width, the crossing angle and the curve radius.
The new cross-section for deep- and flat grooves is represented full scale.
2.2
Calculation of the values for the transverse measurement table
For the calculation of the values for the final transverse measurement table, the creation of
an internal table containing the following is recommended:
For a common crossing with check rails, the values that should be considered are:-
the limiting values of the wheelset check gauge
-
check gauge over crossing flangeway
-
check gauge over check rail flangeway
-
minimum check rail flangeway width,
Originally drafted: March 2004 Issued (in German): May 2006
Translated from the German for UK use January 2009
BOStrab Guidance Regulations (Technishe Regeln Spurführung - TR Sp)
Appendix 2
Page 3 of 8
for wheelsets in both the new and fully worn conditions.
For double crossings, the values that should be considered are:-
the required gauge and check face flangeway widening
-
the building and/or fabrication tolerances.
for the respective curve radius, allowing for the transverse elasticity of the wheels.
The most unfavourable limiting values of the selected gauge and flangeway width are used
to determine the value to be used for the check gauge of the wheelset in the transverse
measurement proofs (cf. section 2.2.5).
If the GGE and track gauging plane do not correspond, (A ≠ a*), it is necessary to undertake
a further conversion to bring the values in the GGE into the track gauging plane by
reference to the inclination of the rail flanks.
2.2.1
Track gauge in the crossing zone - Common crossing / check rail
The nominal track gauge at the common crossing / check rail for the particular track
curve radius is determined from the rounded up total of:Greatest value of the minimum check gauge over crossing flangeway
(obtained from the maximum check gauge in the new and fully worn states
for all bogies under investigation)
plus
for the outside curve (rail), the lateral displacement of the resilient tyre resulting from
the curve dependent (steering) forces and centrifugal force
plus
largest check rail flangeway
(in the new state including the plus fabrication tolerance and/or in the fully
worn state where appropriate)
plus
Absolute value for the minus tolerance for the new track gauge
SEH,min* = LH,min* + WR,max*
(301)
LH,min* from (93)
WR,max* = WR* + ΔW
(302)
WR* from (37)
Originally drafted: March 2004 Issued (in German): May 2006
Translated from the German for UK use January 2009
BOStrab Guidance Regulations (Technishe Regeln Spurführung - TR Sp)
Appendix 2
Page 4 of 8
ΔW Positive manufacturing tolerance for the groove width
SEH,min* = SEH,min* + |-ΔS|
|-ΔS|
2.2.2
(303)
Absolute value for the minus tolerance for the track gauge
Crossing flangeway width for Common crossings
The nominal flangeway width in the common crossing / check rail is calculated from
the sum of:Largest value for the track gauge
(Nominal track gauge + plus building tolerance)
minus
Smallest value for maximum check gauge over the check rail flangeway
(from the minimum check gauge in the new- and fully worn states for the
wheelsets under investigation)
including allowance for the lateral elasticity
plus
Absolute value of the minus manufacturing tolerance for the crossing groove width
WH,min* = SEH,max* - LR,max*
(304)
SEH,max* = SEH* + ΔS
(305)
ΔS = plus building tolerance for the track gauge
LR,max*
from (94)
WH* = WH,min* + |-ΔW|
|-ΔW|
(306)
Absolute value of the minus manufacturing tolerance for the groove
width
2.2.3
Gauge and flangeway width for double crossing
For double crossings, the nominal gauge in the curved track is calculated from the
rounded up total of the values of
Nominal gauge in the straight track
plus
Originally drafted: March 2004 Issued (in German): May 2006
Translated from the German for UK use January 2009
BOStrab Guidance Regulations (Technishe Regeln Spurführung - TR Sp)
Appendix 2
Page 5 of 8
2 x Required gauge widening in the curved track flangeways
(largest value in the new state for all investigated bogies)
plus
absolute value of the minus building tolerance of the track gauge:
SDH,B* = SDH,G* + 2 ΔdS* + I-ΔSI
(307)
I-ΔSI
Absolute value of the minus building tolerance of the track gauge
ΔdS* from (35)
Correspondingly, the nominal flangeway in the curved track of double crossings results from
the rounded up total of:-
Nominal flangeway in the straight track
plus
required gauge face flangeway widening in the curved track
(largest value in the new state for all investigated bogies)
plus
required check face flangeway widening in the curved track
(largest value in the new state for all investigated bogies)
WDH,B*= WDH,G*+ ΔdS*+ ΔdR*
(308)
ΔdS* from (35)
ΔdR* from (34)
With double crossings, the bogie can, depending upon the state of wear of the rails and the
wheels become guided by either the gauge- or check flank of the inner or outer curved rails.
Accordingly and because of the equivalence of both grooves, it is not meaningful to allow for
the lateral elasticity of the wheels.
Originally drafted: March 2004 Issued (in German): May 2006
Translated from the German for UK use January 2009
BOStrab Guidance Regulations (Technishe Regeln Spurführung - TR Sp)
Appendix 2
Page 6 of 8
2.2.4
Gauge and Flangeway width in Flat Groove Rails
In flat groove rail, the wheel is raised through contact between the bottom of the groove and
the tip of the flange. Consequently, the effective values for the wheelset gauge, check
gauge, flange back distance and flange thickness in the gauging plane will be altered
proportionaltely to inclination of the flange flanks (cf. Figure 1.7 in Appendix 1). The
consequent changes relative to the value of the groove depth are the track gauge, check
gauge, distance across groove and/or check rail faces and groove width (a prerequisite is
that the inclinations of the flange flanks and the flat groove flanks correspond).
Deep groove / Flat groove
Track gauge:
ST/F = S - (A + h - tmin - a*) / nS
(309)
Check gauge over crossing flangeway:
LH,T/F = L + (A + h - tmin - a*) / nR
(310)
Check gauge over check rail flangeway:
LR,T/F = L - (A + h - tmin - a*) / nS
(311)
Distance across check rails / groove backs:
KT/F = K + (A + h - tmin - a*) / nR
(312)
Groove width of Flat groove crossing:
WH,F = WH - (A + h - tmin - a*) / nS - (A + h - tmin - a*) / nR
(313)
Flat groove / Flat groove
Track gauge:
SF/F = S - 2(A + h - tmin - a*) / nS
(314)
Check gauge over crossing flangeway:
LH,F/F = L + (A + h - tmin - a*) / nR - (A + h - tmin - a*) / nS
(315)
Distance across check rails / groove backs:
KF/F = K + 2(A + h - tmin - a*) / nR
(316)
Groove width of Flat groove crossing:
WF = W - (A + h - tmin - a*) / nS - (A + h - tmin - a*) / nR analogous to (313)
For S, L, K and W, the respective values for deep groove flangeways are to be used; for h,
that flange height between hmax and hmin at distance (t - a) of the flange tip at which the
maximum and/or minimum flange back distance appears. The value tmin designates the
Originally drafted: March 2004 Issued (in German): May 2006
Translated from the German for UK use January 2009
BOStrab Guidance Regulations (Technishe Regeln Spurführung - TR Sp)
Appendix 2
Page 7 of 8
smallest flat groove depth.
2.2.5
Transverse measurement proof
For straight track, this is just the same as for the turnout / crossing part of the transverse
dimension proof (from section 4.2 of the Technical Rules) to demonstrate (from the rounded
up values of the transverse measurement table) that with the allowable limit values there is
no forcing and that with a deep groove crossing the required minimum wheel support width
is guaranteed.
Common crossing / Check rail:
There should be no overlap, if at the gauge face
SEH,min - WR,max - LH,min > 0
(317)
and at the groove flank
LR,max - (SEH,max - WH,min) > 0
(318)
The magnitude of the clearance (positive result) and/or the overlap (negative result) that
exists at the gauge flank of the crossing is determined from ΔF/ÜF = SEH,min - WH,max - LH,min
(319)
and at the crossing groove flank from
ΔF/ÜR = SEH,max -WH,min -LR,max
(320)
If either of the results from (317) and/or (318) is negative, a negative clearance exists at
either the gauge and/or groove flanks in the crossing. The extent to which this can be
considered acceptable is for the user to determine!
Double crossing:
There should be no overlap (forcing) between the gauge faces, if generally
SDH,min - Smax > 0
(321)
and between the check faces
kmin - (SDH,max - 2 WDH,min) > 0
(322)
Originally drafted: March 2004 Issued (in German): May 2006
Translated from the German for UK use January 2009
BOStrab Guidance Regulations (Technishe Regeln Spurführung - TR Sp)
Appendix 2
Page 8 of 8
SDH,max
Nominal track gauge including plus building tolerance
WDH,min
Nominal flangeway width less the absolute value for the minus
manufacturing tolerance
The magnitude of the clearance (positive result) and/or the overlap (negative result) that
exists at the gauge flanks of the crossing is determined from ΔF/ÜF = SDH,min - Smax
(323)
and at the check flanks from
ΔF/ÜL = kmin - (SDH,max - 2 WDH,min)
(324)
If either of the results from (321) and/or (322) is negative, a negative clearance exists at
either the gauge and/or check flanks in the crossing. The extent to which this can be
considered acceptable is for the user to determine!
The values thus calculated can be inserted into the transverse measurement tables.
3.
Switch Opening
For compliance with section 3.10.2 of the Technical Rules it has to be proved for the
maximum opening between the switch tongue and the stock rail (whether undercut or
recessed) that the flange in both the new and fully worn condition cannot climb on to the
tongue.
Originally drafted: March 2004 Issued (in German): May 2006
Translated from the German for UK use January 2009