RRB Technician Mechanical Syllabus

The RRB Technician Mechanical CBT 2 discipline section tests technical knowledge at the ITI and Diploma level across all major topic areas of the Mechanical trade. It carries 100 questions and 100 marks within the 150-question CBT 2 paper. The CBT 2 score is the sole basis for the final Technician merit list.

Quick Facts: Technician Mechanical

Detailed Mechanical Syllabus

Questions in the Mechanical section test trade theory, applied calculations, materials knowledge, tools and equipment, process steps, quality standards, and safety regulations at the NCVT ITI level. The following topic clusters are covered:

1. Engineering Materials and Metallurgy

•        Iron-Carbon Phase Diagram: phases (ferrite, austenite, cementite, pearlite, bainite, martensite); eutectic (4.3% C; 1147 degrees C); eutectoid (0.83% C; 723 degrees C); lever rule for phase proportion; hypo and hypereutectoid steels

•        Heat Treatment of Steel: annealing (full, process, spheroidising); normalising; hardening (austenitising temperature; quenching media - water, oil, air; martensite formation); tempering (low, medium, high; effect on properties); martempering; austempering; case hardening (carburising - pack, gas, liquid; nitriding; flame hardening; induction hardening)

•        Non-Ferrous Metals and Alloys: aluminium (types - 1xxx to 7xxx series; heat treatable and non-heat treatable; LM alloys); copper and alloys (brass - Cu+Zn; bronze - Cu+Sn; gun metal - Cu+Sn+Zn; cupronickel); titanium; nickel alloys; magnesium alloys; babbit metal (bearing metal)

•        Testing of Materials: tensile test (UTS, yield strength, elongation, reduction of area, Young's modulus - from stress-strain curve); hardness tests (Brinell - BHN = load/spherical area; Vickers - VHN; Rockwell - scales A, B, C; Shore durometer for rubber; Knoop for brittle materials); impact test (Charpy - notch on opposite side to striker; Izod - notch on same side; results in Joules); fatigue test (S-N curve; endurance limit; effect of stress concentration; surface finish); creep test (creep rate; secondary creep; application in high-temperature components)

•        NDT (Non-Destructive Testing): visual inspection (magnifier, endoscope, borescope); liquid penetrant testing (LPT/PT) - colour contrast and fluorescent types; steps (precleaning, applying penetrant, dwell time, removing excess, applying developer, inspection); magnetic particle testing (MPT) - dry and wet methods; circular and longitudinal magnetisation; Yoke method; limitations; ultrasonic testing (UT) - A-scan (CRT display); pulse-echo method; straight and angle beam probes; applications in rail and wheel testing; radiographic testing (RT) - X-ray and gamma ray (Ir-192, Co-60); film processing; IQI; ASME Section V; eddy current testing (ET) - for surface and near-surface defects in conductive materials

2. Fluid Mechanics and Hydraulic Machinery

•        Fluid Properties: density; specific gravity; dynamic and kinematic viscosity; surface tension; capillarity; compressibility (bulk modulus)

•        Fluid Statics: hydrostatic pressure p = rho g h; pressure on plane and curved submerged surfaces; centre of pressure; buoyancy (Archimedes principle); metacentre; stability of floating bodies

•        Fluid Kinematics: types of flow (steady/unsteady; uniform/non-uniform; laminar/turbulent; compressible/incompressible); Reynolds number Re = rho V D / mu; streamlines, streaklines, pathlines; continuity equation (conservation of mass)

•        Fluid Dynamics: Bernoulli's equation (p/rho g + V^2/2g + z = constant); modified Bernoulli with losses; Euler's equation; momentum equation (force on pipe bend; pipe reducer; jet striking plate)

•        Flow Measurement: venturimeter (Cd ~0.97; Q = Cd x A1 A2 sqrt(2g Delta h) / sqrt(A1^2 - A2^2)); orifice meter (Cd ~0.64); pitot tube (V = sqrt(2gh)); rotameter; magnetic flowmeter; ultrasonic flowmeter

•        Pipe Flow: Darcy-Weisbach equation (hf = f L V^2 / 2gD); friction factor (Moody chart; Blasius formula for turbulent flow in smooth pipes); Hagen-Poiseuille equation (laminar flow); minor losses (entry, exit, valve, elbow - K coefficients); equivalent pipe length; siphon; water hammer

•        Open Channel Flow: Manning's formula V = (1/n) R^(2/3) S^(1/2); Chezy's formula V = C sqrt(RS); specific energy (E = y + V^2/2g); critical depth; critical flow conditions; hydraulic jump (energy dissipation; conjugate depths; Froude number); gradually varied flow (profiles - M1, M2, M3, S1, S2, S3)

•        Turbines: Pelton wheel (impulse; tangential; velocity triangle; work done; efficiency; speed ratio); Francis turbine (mixed flow; reaction; specific speed; cavitation; draft tube; efficiency vs speed); Kaplan turbine (axial flow; adjustable blades; high specific speed); cavitation (causes; effects; sigma - Thoma's cavitation number; prevention - setting height of turbine, draft tube)

•        Pumps: centrifugal pump (construction; working; specific speed; characteristic curves - H-Q, P-Q, eta-Q; NPSH - Net Positive Suction Head; cavitation; priming; series and parallel operation; affinity laws); reciprocating pump (single-acting, double-acting; slip; indicator diagram; air vessel); axial flow pump; selection criteria

3. Thermodynamics and Heat Transfer

•        Basic Concepts: system (open, closed, isolated); properties (intensive, extensive); state; process (isothermal, adiabatic, isobaric, isochoric, polytropic n); cycle; zeroth law; thermometric property

•        First Law: internal energy; enthalpy; SFEE (steady flow energy equation - Q - W = Delta H + Delta KE + Delta PE); applications (nozzle: KE increases, H decreases; diffuser; turbine; compressor; heat exchanger; throttling: h1 = h2)

•        Second Law: Kelvin-Planck and Clausius statements; heat engine, refrigerator, heat pump; Carnot cycle (efficiency eta = 1 - TL/TH); Carnot refrigerator (COP = TL/(TH-TL)); entropy (ds = dQ_rev/T; entropy generation in irreversible processes); T-S diagram; availability and irreversibility

•        Pure Substances: p-v-T surface; saturation curve; triple point; critical point; wet region; superheated vapour; compressed liquid; quality (dryness fraction) x = mg/(mg + mf); steam tables (saturation table by T and by P; superheated steam table; interpolation); Mollier (h-s) diagram; throttling (h = constant) and its use on Mollier chart

•        Gas Power Cycles: Otto cycle (spark ignition petrol engine; efficiency = 1 - 1/r^(gamma-1); r = compression ratio); Diesel cycle (compression ignition diesel engine; efficiency = 1 - r_c^gamma - 1 / gamma(r_c-1) / r^(gamma-1); r_c = cut-off ratio); Dual cycle (efficiency; comparison with Otto and Diesel; same conditions); Brayton (Joule) cycle (gas turbine; compressor, combustion chamber, turbine; back work ratio; intercooling; regeneration; reheating)

•        Vapour Power Cycles: Rankine cycle (pump, boiler, turbine, condenser; efficiency; thermal efficiency formula; effect of boiler pressure and superheat; dry and wet turbine exit); reheat Rankine cycle (advantage - increased efficiency and dry turbine exit); regenerative Rankine cycle (open and closed feedwater heaters; thermal efficiency improvement)

•        Refrigeration Cycles: vapour compression refrigeration cycle (VCC) - components (compressor, condenser, expansion valve, evaporator); p-h diagram; COP = RE/W; sub-cooling and superheating effects; vapour absorption cycle (ammonia-water; LiBr-water; advantages - no moving parts; COP less than VCC)

•        Psychrometrics: dry-bulb temperature (DBT); wet-bulb temperature (WBT); dew point temperature (DPT); specific humidity omega = 0.622 Pv/(P-Pv); relative humidity phi = Pv/Psat; enthalpy h = hf + omega hfg; psychrometric chart; processes (sensible heating, sensible cooling, humidification, dehumidification, adiabatic mixing)

•        Conduction: Fourier's Law q = -kA dT/dx; thermal conductivity; thermal resistance (plane wall, cylinder, sphere); composite walls; overall heat transfer coefficient U; critical radius of insulation; fins (fin efficiency, fin effectiveness, heat transfer from fin)

•        Convection: Newton's Law of Cooling q = hA(Ts - Tf); convection coefficient h; dimensionless numbers (Re - inertia/viscous; Nu - convective/conductive; Pr - momentum/thermal diffusivity; Gr - buoyancy/viscous for natural convection); correlations for forced convection (Dittus-Boelter for turbulent flow in pipe; Churchill-Bernstein for cylinder cross flow)

•        Radiation: Stefan-Boltzmann law q = epsilon sigma A T^4; emissivity; absorptivity; reflectivity; transmissivity; Kirchhoff's Law (epsilon = alpha at same temperature); view factors (shape factors); radiation heat exchange between black and grey surfaces; radiation shields; greenhouse effect

•        Heat Exchangers: types (parallel flow, counter flow, cross flow, shell-and-tube); LMTD method; NTU-effectiveness method (maximum heat transfer; effectiveness as function of NTU and Cr); fouling resistance; TEMA standards

4. Theory of Machines and Machine Design

•        Kinematics of Machines: kinematic pairs; kinematic chains; mechanism; inversions of four-bar chain (crank-rocker, drag-link, double-crank, double-rocker); slider-crank inversions (quick return - Whitworth, Crank and Slotted Lever; Oscillating cylinder; Hand pump); Grashof's condition

•        Velocity and Acceleration Analysis: relative velocity method; instantaneous centre method (number of IC = n(n-1)/2); Klein's construction for slider-crank; Coriolis acceleration (2 omega x v for slider on rotating link)

•        Gears: terminology (pitch circle diameter, module m = d/T, circular pitch p = pi m, diametral pitch Pd = T/d, addendum, dedendum, clearance, backlash, pressure angle - standard 20 degrees; tooth depth); law of gearing (common normal to tooth profiles must pass through pitch point); involute and cycloidal tooth profiles; gear ratio; simple, compound, and epicyclic gear trains; gear tooth forces (tangential, radial, axial for helical)

•        Cams and Followers: types of cams (disc cam with radial follower - uniform velocity motion, SHM, uniform acceleration and deceleration, cycloidal); pitch curve; base circle; follower motion curves; pressure angle and undercutting; types of followers

•        Balancing: static and dynamic balancing of rotating masses; balancing of reciprocating masses (primary and secondary forces; primary and secondary couples); V-engine balancing; balancing machines

•        Governors: Watt; Porter; Proell; Hartnell; Hartung; Wilson-Hartnell; centrifugal governors - speed regulation; range of speed; coefficient of insensitiveness; hunting; isochronism; sensitivity

•        Flywheels: fluctuation of energy; fluctuation of speed (cs); coefficient of fluctuation of speed; design of flywheel (cast iron - permissible hoop stress; rim and hub)

•        Clutches and Brakes: single plate clutch (uniform pressure and uniform wear theories); multi-plate clutch; cone clutch; centrifugal clutch; band brake; block brake; disc brake

•        Vibrations: free vibration (SDOF - undamped natural frequency omega_n = sqrt(k/m); period T = 2pi/omega_n; damped - damping ratio zeta; over, critical, underdamped); forced vibration (frequency ratio r = omega/omega_n; magnification factor; resonance); transmissibility; vibration isolation

•        Machine Design Basics: types of loading (static, dynamic, impact); factor of safety; stress concentration factor (Kt); endurance limit (Se); surface finish factor; size factor; reliability factor; Goodman and Soderberg failure criteria; design of shafts (ASME code; combined bending and torsion)

5. Manufacturing Engineering and Metrology

•        Casting: pattern design; allowances (shrinkage, draft, machining, distortion); types of moulding (sand, die, investment, shell, centrifugal, continuous); gating system (sprue, runner, gate, riser); casting defects (shrinkage cavity, cold shut, misrun, blow hole, hot tear, shift, fin)

•        Forming: forging (types - open die, impression die, drop forging; operations - upsetting, drawing down, edging, fullering; defects); rolling (hot and cold; passes; defects); extrusion (direct - ram speed; indirect; impact; hydrostatic; extrusion ratio; hot and cold); drawing (deep drawing; blank diameter; DRR - Drawing Ratio; earing; wrinkling; tearing); sheet metal operations (shearing; blanking; piercing; bending - springback; deep drawing - BHF; Forming Limit Diagram FLD)

•        Welding (Manufacturing): arc welding processes (SMAW; GMAW/MIG; GTAW/TIG; SAW; PAW); heat input (Q = VI x 60 / v); dilution; weld symbol reading; heat affected zone; weld distortion control; soldering; brazing; friction welding; friction stir welding; electron beam welding; laser beam welding

•        Machining: orthogonal and oblique cutting; chip types (continuous, continuous with BUE, discontinuous); Merchant's circle; specific cutting energy; cutting tool geometry; tool life Taylor's equation VT^n = C; cutting speed, feed, depth of cut, MRR; turning; milling (peripheral and face; up and down milling; indexing); drilling (drill geometry; drill diameter selection; drill jig); grinding (wheel marking system; dressing; glazing; loading; burning; chatter)

•        CNC Technology: CNC advantages; types of CNC systems; G-codes (G00, G01, G02, G03, G04, G40, G41, G42, G54-G59, G71, G81-G84, G90, G91, G94, G95, G96, G97); M-codes (M00, M01, M03, M04, M05, M06, M08, M09, M30); tool offset (wear and geometry); CNC lathe and machining centre programming; CAM workflow; DNC and FMS concepts

•        Metrology and Quality Control: limits, fits, and tolerances (IS 919; hole and shaft basis; fundamental deviations; IT grades IT01 to IT18; Go/No-Go gauges); surface finish (Ra, Rz, Rmax; CLA; measuring instruments - profilometer, surface roughness comparator); geometric tolerances (GD&T - flatness, straightness, roundness, cylindricity, parallelism, perpendicularity, runout, concentricity - ISO 1101 symbols); SPC (control charts X-bar and R; p-chart; np-chart; c-chart; u-chart; process capability Cp and Cpk)

6. Industrial Engineering

•        Work Study: method study (process chart, operation chart, flow chart, string diagram); time study (elements; basic time; allowances; standard time; efficiency); work sampling (confidence level; sample size; productivity index)

•        Production Planning: types of production (job, batch, mass, continuous); plant layout (process, product, fixed position, cellular); material handling (conveyors, cranes, forklifts, AGV); production scheduling (Gantt chart; loading; sequencing - Johnson's algorithm for two machines)

•        Inventory Control: EOQ model (derivation; assumptions; optimal order quantity; total cost); price break (incremental and all-unit discounts); safety stock; reorder point (ROP); ABC analysis; JIT concept; kanban

•        CPM and PERT: network construction (AON and AOA); EST, EFT, LST, LFT; critical path; float (total, free, independent); project crashing (cost-time tradeoff); PERT (probabilistic time estimates; expected time; variance; probability of completion)

•        Quality Management: TQM; quality costs (prevention, appraisal, internal failure, external failure); ISO 9001:2015 (clauses; PDCA cycle); Six Sigma (DMAIC; DFSS; defects per million opportunities DPMO; sigma level); FMEA (severity, occurrence, detection; RPN); reliability (MTTF; MTBF; MTTR; failure rate; bathtub curve; series and parallel reliability)

7. Railway Mechanical Engineering

•        Railway Track and Permanent Way: components (rail, sleeper, ballast, fastenings); rail sections (90R, 52 kg, 60 kg UIC - weight per metre; head, web, foot dimensions); sleeper types (wooden, CST-9 steel, concrete - mono block, twin block); ballast materials and specifications; creep (causes, measurement, prevention - anti-creep devices); rail joints (fish plated, welded - flash-butt, thermite/aluminothermic); coning of wheels (1 in 20); rail inclination (1 in 20); gauge types (broad 1676mm, metre 1000mm, narrow 762mm, 610mm)

•        Rolling Stock - Locomotives: diesel locomotive (ALCO WDM2, WDG3A - 16-cylinder 251-B engine; power transmission - hydraulic (DH); electric (DE) - traction motors; bogies; braking - dynamic, rheostatic); electric locomotive (WAP-4, WAP-5, WAP-7, WAG-9 - specifications; traction motors - DC series on WAP-4; AC induction on WAP-7/WAG-9; IGBT converter; regenerative braking; pantograph)

•        Rolling Stock - Coaches: ICF coach (integral coach factory Perambur; underframe; body; bogie - ICF design; axle - solid steel; wheel diameter 915mm); LHB coach (Linke-Hofmann-Busch Germany/RCF Kapurthala; FIAT bogie; CBC couplers; anti-climbing feature; longer life 30 years vs 25 years ICF; self-centering automatic coupler); air conditioning (RMPU - Roof Mounted Package Unit; under-slung unit; 3kW to 7.5kW per coach; refrigerant R134a)

•        Rolling Stock - Wagons: BOXN (open wagon for coal and iron ore; CASNUB bogie); BCNA (covered wagon); BTPN (tank wagon for petroleum); BVZC (brake van); CONCOR flat wagons for container traffic; wagons per train; axle load (25 tonne on EMU/BG; 22.9 tonne on HM class)

•        Braking Systems on Trains: vacuum brake (creating vacuum; brake cylinder; brake block; distributor valve; graduated application); air brake (twin pipe and single pipe; ARES; KNORR-BREMSE; ABDX; graduated release; composition brake blocks - non-asbestos; WDP-4 and WAP-7 regenerative braking); BVZC (brake van - guard van)

•        Coupler and Buffer: CBC (Centre Buffer Coupler) on LHB coaches; screw coupler on ICF coaches; draft gear; buffer springs; coupler strength; uncoupling mechanism

•        Wheel and Axle: coning (1 in 20); tread profile (UIC 60 profile); back-to-back dimension (1600mm +-2mm for BG); flange thickness; flange height; wheel diameter (915mm when new; condemning size 825mm); axle types (loaded axle; engine axle); axle turning; ultrasonic testing of axles and wheels (UT of solid axles and wheels using angle beam probe)

•        Maintenance and POH: POH (Periodic Overhaul) schedule for ICF and LHB coaches (18 months intervals); schedule maintenance (A, B, C, D schedules for locomotives); hot box detection (TADS - Track side Acoustic Detection System; hot axle box); derailment investigation (OIR - Ongoing Inquiry Report; speed calculation from wheel mark distance)

Common Technical Section (50 Questions)

In addition to the 100-mark trade section, all Technician candidates must answer the following 50-mark common section in CBT 2:

Physics and Chemistry (20 Questions - Class 12 / Diploma Level)

•        Physics (Class 12 / Diploma Level): Units and Measurement; Motion (kinematics; Newton's Laws); Work, Energy and Power; Properties of Matter (elasticity, viscosity, surface tension); Heat and Thermodynamics (specific heat, latent heat, laws of thermodynamics, Carnot cycle); Sound (wave motion, Doppler effect, resonance); Light (laws of reflection and refraction; lenses and mirrors; Young's double slit; diffraction; polarisation); Electrostatics (Coulomb's Law, capacitance, dielectrics); Current Electricity (Ohm's Law, Kirchhoff's Laws, Wheatstone bridge, power); Magnetic Effects of Current (Biot-Savart, Ampere's Law, force on conductor); Electromagnetic Induction (Faraday and Lenz); AC Circuits (RMS, LCR, resonance, power factor); Semiconductor Devices (p-n junction, transistor basics, logic gates); Modern Physics (photoelectric effect, radioactivity, nuclear reactions)

•        Chemistry (Class 12 / Diploma Level): Atomic Structure (Bohr model, quantum numbers, electronic configuration); Periodic Table (periodicity, s, p, d, f blocks, periodic trends); Chemical Bonding (ionic, covalent, metallic, VSEPR, hybridisation); States of Matter (gas laws - Boyle's, Charles's, Avogadro's; ideal and real gases); Thermodynamics (enthalpy, Hess's Law, entropy, Gibbs free energy); Chemical Equilibrium (Le Chatelier's principle, Kp, Kc); Electrochemistry (electrode potential, Nernst equation, electrolysis, Faraday's Laws, corrosion); Chemical Kinetics (rate law, order, activation energy, Arrhenius equation); p-Block Elements (Groups 15 to 18 - properties, compounds, oxoacids); d-Block Elements (transition metals, oxidation states, colour); Organic Chemistry (reactions SN1, SN2, E1, E2; IUPAC nomenclature; functional groups; biomolecules); Polymers and Chemistry in Everyday Life

Basics of Computer Applications (15 Questions)

•        Computer Applications Basics (Class 10 / ITI Level): Computer components (CPU, RAM, ROM, storage - HDD, SSD; I/O devices; ports); Operating system functions; MS Office (Word - formatting, tables, find-replace; Excel - formulae SUM, AVERAGE, IF, VLOOKUP, charts; PowerPoint - slides, transitions); Internet (browser, search engine, URL, HTTP, HTTPS, email, online safety); File management (folders, file types, copy, move, delete, zip); Network basics (LAN, WAN, Wi-Fi, IP address, router, modem); Cybersecurity (password best practices, phishing, antivirus, firewalls); Binary, octal, hexadecimal number systems and conversion; Logic gates (AND, OR, NOT, NAND, NOR, XOR) - truth tables and Boolean expressions

Environment and Pollution Control (15 Questions)

•        Environmental and Pollution Control (Class 10 / ITI Level): Types of pollution - Air (pollutants: PM2.5, PM10, SOx, NOx, CO, VOCs; sources; health effects; vehicular emission norms BS6; AQI); Water (BOD, COD, DO; sources of water pollution; effects; treatment methods - primary, secondary, tertiary); Soil (pesticides, heavy metals, plastic; remediation); Noise (dB scale; CPCB limits; control measures); Solid Waste Management (classification; 3R principle; composting; sanitary landfill; e-waste; plastic waste rules; biomedical waste); Renewable Energy (solar PV and thermal; wind; hydro; biomass; geothermal; hydrogen; India's renewable targets); Climate Change (greenhouse gases; global warming; Paris Agreement; India's NDC); Environmental Legislation (EPA 1986; Air Act 1981; Water Act 1974; Forest Conservation Act; Wildlife Protection Act; National Green Tribunal); Indian Railways Green Initiatives (bio-toilets; solar energy on trains and stations; LED lighting; rainwater harvesting; ISO 14001; plastic-free stations)

Preparation Strategy

1. NCVT ITI Mechanical Trade Theory is the Primary Source

The NCVT-prescribed ITI textbooks for the Mechanical trade (published by DGT or state ITI boards) are the most accurate and exam-aligned source. Read every chapter systematically, noting definitions, formulae, IS codes, process steps, safety rules, and tool specifications.

2. Focus on Factual, Numerical, and Standards-Based Content

MCQs in the trade section frequently test specific technical values, IS code provisions, standard formulations, and process parameters. Memorise standard values (voltage levels, wire gauges, material properties, temperature limits, safety clearances) for reliable marks.

3. Practise from SSC JE and RRB Technician Question Banks

Solve previous years' RRB Technician and SSC JE Mechanical question banks for difficulty calibration and exposure to typical question formats. Previous paper analysis reveals the most frequently tested topics.

Frequently Asked Questions

Q1. Is the Mechanical Technician syllabus the same as the JE Mechanical syllabus?

The topics overlap but the Technician paper is at ITI level while the JE paper is at Diploma/Degree level. JE questions are more analytical and deeper; Technician questions are more applied and practical at the trade level.

Q2. Are IS codes tested in the Technician trade section?

Yes. Questions on relevant IS codes, safety standards, and BIS specifications for the trade appear regularly. Prepare a list of key IS codes applicable to your trade.