Riding Quality and Riding Index

The riding comfort experienced by a passenger in a coach depends not only on his individual sensitivity but also in displacement, acceleration, rate of change of

acceleration and factors like noise, dust humidity and temperature etc. There are 2 important methods of evaluation which are commonly used for expressing comfort:-

1. Method of fatigue time.

2. Method of ride index

The Riding quality is the function of track defect its frequency and vehicle characteristics. Therefore it is essential to limit the size of defect for safety of train operation.

SPERLING RIDE INDEX

R.I. = 0.896 x {b³ x F(f)/ f }¹/¹º

Where, b = Average of cubes of acceleration peaks (cm/sec²).

            f = Frequency in Hz.

          F (f) = Function of frequency that takes into account the human reaction to

                     frequency of acceleration.

For Vertical mode

F (f) = 0.325 x f ²              for 0.5 < f <= 5.9 Hz

    = 400/f ²                        for 5.9 < f <= 20 Hz

    = 1                                 for f < 20 Hz

For Lateral Mode

F (f) = 0.80 x f ²                for 0.5 < f <= 5.4 Hz

        = 650/ f ²                   for 5.4 < f <= 26 Hz

         = 1                           for f > 26 Hz

Value of RI generally varies from 1 to 5. Interpretation of RI for riding is as under:

CONDITION OF TRACK STRUCTURE

There are five components of a track, namely rails, sleepers, fittings and fastenings, ballast and formation. Each component inspected minutely and defects are rectified.

(A) Rails: - Observed physically for surface defects.

(B) Sleepers: - Depending on the type of sleepers. Defects are recorded like broken, bent, damaged etc.

(C) Fittings and Fastenings: - Ineffective fastening are replaced and missing fittings are provided.

(D) Ballast:- Location of deficient ballast is noted and deficiency are recouped

(E) Formation:- Low cess and bridge approaches are identified for incorrect ballast profiles. Side drains and catch water drains are inspected near deep cuttings and tunnels.

TRACK GEOMETRY

Track geometry is recorded by measuring track parameters using TRC’s and monitored:-

(A) Peak Based

• It helps in identifying isolated localized defects.

• It helps in isolated attentions & MMU-I.

(B) Standard Deviation Based

• It helps in identifying bad stretches.

• It is useful in deciding machine maintenance.

Correct Method of Work and Protection

During on foot inspection, push trolley inspection and motor trolley inspection gang is inspected for correct method of working and their knowledge of protection rules.

Counseling of track man, patrol man and gate man should be done once in a month during inspection by PWI, ADEN and their acknowledgements should be taken in a register.

Purpose of Manual Inspection

• Inspection of track structure

• Inspection of Gang working

• Field verification of track defects

• Inspection of other track related items