2. MOLB with Mechanical Boom
Locking.
In MOLB,
After closer of boom and
resting on to the meeting
post gate man will operate
the single way GF lever frame
which locks boom through
rod operation.
Demerit
With out closure of Gate
boom locking key from E-
Type lock fixed on GF frame
can be extracted when E-type
lock worn out condition
etc.,During this situation
signal can be taken OFF in
gate open condition.
3. EOLB with Solenoid Boom Locking
In EOLB,
Once boom closes and resting
on meeting post the locking
hook in the meeting post will
be automatically locks the
boom by counter weight
arrangement
Proximity switch in the
meeting post will be activated
and gate close indication
transmitted to panel
automatically
4. EOLB with Solenoid Boom Locking
RDSO/SPN/180/2005
Demerits
Gate close indication very
frequently disturbed by in-
disciplined road users during
their passage.
Solenoid boom locking also
getting failed frequently due
to its fragile design.
5. EOLB with Solenoid Boom Locking RDSO /SPN/180/2005
Failure Investigation
CASE STUDY Due to fast operation of booms
At PPZ Station LC Gate No. 52 by gate man LC Gate close
EOLB boom lifted off from indication appeared and
meeting post without sticked through BLR relay front
disturbing the close contact. This is as per circuit
indication. The angle of open design. Stick contact
was found around 5 degrees. incorporated in the circuit to
Angle of open 5 degree if avoid frequent gate close
convert into Meters is directly indication disturbance caused
proportional to length of the by road users. By this stick
boom, that means shorter contact due to swinging action
length of the boom will have of boom in the meeting post
less opening than longer proximity switch activated and
length of the boom, this can gate close indication was
sometimes allow road vehicle
permanently available though
to pass.
the boom was unlocked and
lifted OFF from boom.
6. Solenoid Boom Locking
hook was found permanently
held unlocked position. The
reason for this failure may be
residual magnetism in the
Solenoid Coil or may be
mechanical stuck up.
Residual Magnetism in the
coil could not be ruled out
because the armature was
operating with higher
current range.
7. EOLB with Mechanical Boom Locking
Rack & Pinion Lever to be installed adjacent to Underneath of the gate lodge vertical crank to
Gate man operating EOLB panel in the Gate be fixed to convert the vertical motion into
Lodge for EOLB boom locking operation Horizontal motion of rod run.
8. EOLB with Mechanical Boom Locking
Existing EOLB meeting post to be replaced
with Mechanical meeting post duly fixing After boom operation completed the key will
mechanical RDSO boom locking arrangement. be extracted from the lever and transmitted to
After Boom resting on meeting post gateman Station through EKT,
will operate the Rack & Pinion Lever which will
enable the locking of Booms.
9. By providing Mechanical Boom locking on EOLB’s
1. Signal Restoring back to Red in the face of train due to
disturbance of gate close indication by road users
eliminated.
2. Positive Boom locking achieved.
3. Extraction of Boom locking key from lever without closing
gate intentionally or unintentionally signal cannot be
lowered because in gate close indication circuit closer of
boom (0-5 degree) in series with EKT contact proved.
