BEML Junior Executive key terms

The company that designs and builds the equipment, such as a truck, excavator or metro coach, and supplies genuine spare parts, drawings and technical support for it.

The maximum weight of material a machine such as a haul truck or dumper is rated to carry, excluding the weight of the vehicle itself.

The total permissible weight of a vehicle including its own structure, fuel, operator and payload, used to check road limits and tyre ratings.

The ratio of the actual volume of material a bucket holds to its rated struck capacity, reflecting how loosely or tightly the material heaps.

The time a machine takes to complete one full working sequence, such as digging, swinging, dumping and returning, used to estimate productivity.

The volume of waste rock or overburden that must be removed to extract one unit of ore or coal, a key measure of mining cost and feasibility.

The layer of soil and rock lying above a coal seam or ore body that must be drilled, blasted and removed before the mineral can be mined.

The vertical height of a single mining step or terrace from which material is excavated, usually matched to the reach of the excavator and drill depth.

A drilled hole in rock that is charged with explosive and fired so that rock breaks into fragments that can be loaded and hauled.

The slope of a mine transport road expressed as a percentage, which directly affects the speed, fuel use and safe braking of loaded haul trucks.

The thickness of rubber remaining on a tyre's contact surface; below the specified limit the tyre must be replaced for grip and safety on haul roads.

Scheduled servicing carried out at fixed intervals of running hours or kilometres to replace wear parts and prevent unexpected breakdowns of equipment.

Using measurements such as vibration, oil analysis and temperature to track equipment health and decide maintenance before a fault causes a stoppage.

The average running time between one failure and the next for a repairable machine or component, used to judge reliability and maintenance effectiveness.

The average time needed to restore a failed machine or component to working condition, including diagnosis, spare part fitment and testing.

The formal process of raising a documented request for spare parts, listing part numbers, quantities and urgency, so that procurement can place orders.

A request to the manufacturer or supplier to repair or replace a failed item free of cost within the agreed warranty period and conditions.

A track width of 1,435 millimetres measured between the inner faces of the rails, used by most high-speed and metro systems worldwide.

A track wider than the standard 1,435 millimetres; Indian Railways broad gauge is 1,676 millimetres and carries most of its passenger and freight traffic.

A track width of 1,000 millimetres between the rail inner faces, historically common on lighter-traffic and hilly routes in India.

Crushed stone laid under and around sleepers to hold the track in position, spread load and drain rainwater away from the track structure.

The transverse member, made of concrete, wood or steel, that supports the rails and keeps them at the correct gauge and inclination.

The clip, bolt or elastic assembly that holds the rail firmly to the sleeper and resists longitudinal, lateral and vertical forces from trains.

A track arrangement of switches and crossings that lets trains move from one track to another, a high-maintenance location needing strict inspection.

The powered mechanism, electric or electro-pneumatic, that moves and locks switch rails at a turnout and confirms the set position to signalling.

The inward tilt given to the outer rail on a curve, raising it above the inner rail to balance centrifugal force and improve passenger comfort.

A signalling safety arrangement in which signals and points are locked so that conflicting train movements cannot be set up at the same time.

An onboard and trackside system that supervises train speed and applies brakes if the driver exceeds permitted limits or ignores a restrictive signal.

A system that drives trains automatically for part or all of a journey, controlling acceleration, braking and stopping at platforms under supervision.

A braking method in which traction motors act as generators, converting train momentum into electrical energy that is returned to the supply or stored.

An additional current-carrying rail mounted alongside the running rails that supplies traction power to a train through a collector shoe.

The catenary and contact wire system suspended above the track that delivers traction current to the train through a pantograph.

The electric motor mounted on a locomotive or coach that converts electrical energy into rotating force to drive the wheels through a gear set.

The wheel-set frame assembly under a coach or wagon that carries the body, guides it along the track and absorbs vibration through springs and dampers.

A pair of wheels pressed onto a common axle, maintained as a matched unit and inspected for diameter difference, flange wear and cracks.

The angle between an aircraft wing's chord line and the oncoming airflow, which governs lift and drag and must stay below the stall angle.

A sudden loss of lift when the angle of attack exceeds a critical value and airflow separates from the wing, requiring the nose to be lowered to recover.

The ratio of lift produced to the aircraft's weight; in a level turn it rises above one, increasing stall speed and structural loading.

The maximum altitude at which an aircraft can still climb at a specified minimum rate under given weight and atmospheric conditions.

The ratio of an aircraft's speed to the local speed of sound; values above one indicate supersonic flight with shock waves and changed lift behaviour.

The ratio of air flowing through a turbofan's bypass duct to air passing through the engine core, a key measure of fuel efficiency and noise.

Engine thrust divided by aircraft weight; a higher value gives better acceleration and climb performance and enables sustained flight without lift loss.

The angle between the wing chord line and the relative airflow, controlling lift generation and determining when a wing will stall.