Some important Abbreviations related to Indian Railway
Abbreviation Stands For
AEN/MC Assistant Engineer/Machines
BCM Ballast Cleaning Machine
BFR...
more...

Bogie Flat for Rails
BRM Ballast Regulating Machine
CE Chief Engineer
CEE Chief Electrical Engineer
CFO Chief Foreman
CME Chief Mechanical Engineer
CMM Chief Material Manager
CN Construction
COM Chief Operating Manager
COS Controller of Stores
CPOH Central Periodical Overhauling
CRF Capital Recovery Factor
CRS Commissioner of Railway Safety
CSM Continuous Tamping Machine
CSP Concreate Sleeper Plant
CSTE Chief Signal & Telecommunication Engineer
CTE Chief Track Engineer
CTR Composite Track Record
CWR Continuous Welded Rail
DEN Divisional Engineer
DOT Department of Telecommunication
DSK Depot Store Keeper
DTS Dynamic Track Stabilizer
DUO Duomatic Machine
Dy.CE/TT Deputy Chief Engineer/Tie Tamping
ETKM Equated Track Kilometer
FP Fish Plate
GR General Rules
G&SR General & Subsidiary Rules
GC Gauge Conversion
GM General Manager
GMT Gross Million Tonnes
GPM Gallon Per Minute
GVA Geometry Value Assessment
HP Horse power
HQ Headquarter
Hrs. Hours
HS Hand Signal
HSD High Speed Diesel
HSK Highly Skilled
I/C Incharge
IOH Intermediate Overhauling
IR Indian Railways
IRICEN Indian Railways Institute of Civil Engineering Pune
IRPWM Indian Railways Permanent Way Manual
IRTMTC Indian Railways Track Machines Training Centre
JA Grade Junior Administrative Grade
JE Junior Engineer
LV Last Vehicle
LWR Long Welded Rail
MAS Material At Site
MC Machines
MCI Malleable Cast Iron
MOU Memorandum of Understanding
MPT Multipurpose Tamper
OEM Original Equipment Manufacturer
OHE Overhead Equipments
P Way Permanent Way
PCB Printed Circuit Board
POH Periodical Overhauling
PQRS Plasser's Quick Relaying System
PRC Prestressed Reinforced Concrete
PSC Prestressed Concrete
RGM Rail Grinding Machine
RPM Revolutions per minute
S&D Supply & Disposal
S&T Signal & Telecommunication
SBC Shoulder Ballast Cleaner
SBCM Shoulder Ballast Cleaning Machine
SE Section Engineer
SEJ Switch Expansion Joint
SEN Senior Engineer
SM Station Master
SPURT Car Self Propelled Ultrasonic Rail Testing Car
Sr. DEN Senior Divisional Engineer
Sr.DOM Senior Divisional Operating Manager
SSE/MC Senior Section Engineer/Machines
SSO Senior Stores Officer
TM Track Machine
TRT Track Relaying Train
TTM Tie Tamping Machine
UNIMAT Points and Crossing Tamping Machine
UNO Unomatic Machine
USFD Ultrasonic Flaw Detection
UT Universal Tamper
UTV Utility Track Vehicle
VHF Very High Frequency

Source of this info: click here
Apart from the above abbreviations you can find the Pictures or Graphics of important railway machineries by clicking on the link given below:
click here
A page will be opened when you click on the above link. Then click on the name of each machines to see their sketch.

Attached Images:
Ballast Regulator(Model 56-3)
Image Link: click here
Ballast Regulator(Model 66-4)
Image Link: click here
Good quality track ballast is made of crushed stone. The sharp edges help the particles interlock with each other
Image Link: click here

What is ballast regulator?
Ans: A ballast regulator is a piece of rail transport maintenance of way equipment used to shape and distribute the gravel track ballast that supports the ties in rail tracks. They are often used in conjunction with ballast tampers when maintaining track.
For more details please refer: click here
What is track ballast?
Ans: Track ballast forms the trackbed upon which railway sleepers (UK) or railroad ties (US) are laid. It is packed between, below, and around the ties.It is used to bear the load from the railroad ties, to facilitate drainage of water, and also to keep down vegetation that might interfere with the track structure.This also serves to hold the track in place as the trains roll by. It is typically made of crushed stone, although ballast has sometimes consisted of other, less suitable materials. The term "ballast" comes from a nautical term for the stones used to stabilize a ship.
For more details on track ballast please refer: click here