Railcar Axle Load
Calculate a rail vehicle's axle load, P_axle = total weight ÷ number of axles, from the gross weight of the wagon or locomotive (N, tare plus load) and the number of axles. Axle load is the most important parameter for track design: it is the force each axle transmits to the track (and, per wheel, to each rail), governing stresses in the rail, sleepers, ballast and subgrade. Railways are classified by their axle-load capacity: heavy-haul railways (such as ore lines) run at 30-40 tonnes per axle and need heavy rail, concrete sleepers and reinforced ballast; passenger and light-freight lines run lower loads. Exceeding the allowable axle load causes accelerated fatigue, permanent deformation and failures — so rolling-stock and track-class compatibility is strictly controlled. Axle load also limits maximum train weight and thus transport productivity. Enter the total weight and the number of axles.
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Carga por eixo de vagão
A carga por eixo de um veículo ferroviário é P_eixo = peso bruto total ÷ número de eixos, a partir do peso bruto do vagão ou da locomotiva (incluindo a tara mais a carga transportada) e do número de eixos. A carga por eixo é o parâmetro mais importante para o dimensionamento da via permanente: é a força que cada eixo transmite à via (e, dividida pelas rodas, a cada trilho), e dela dependem as tensões no trilho, nos dormentes, no lastro e na plataforma de terraplenagem. As ferrovias são classificadas pela sua capacidade de carga por eixo: as de carga pesada (heavy haul, como as grandes ferrovias de minério da Austrália, do Brasil e da África) operam com 30 a 40 toneladas por eixo e exigem trilhos pesados, dormentes de concreto, lastro espesso e plataforma reforçada; já as ferrovias de passageiros e de cargas leves operam com cargas bem menores e via mais leve. Exceder a carga por eixo admissível da via é perigoso e custoso: causa fadiga acelerada do trilho, deformação permanente do lastro e da plataforma, e falhas que levam a restrições de velocidade ou interdições — por isso a compatibilidade entre o material rodante e a classe da via é rigorosamente controlada por norma. A carga por eixo também limita o peso máximo dos trens e, portanto, a produtividade do transporte ferroviário (mais carga por eixo = trens mais pesados = mais carga por viagem). É o número que, em última análise, define o que uma ferrovia pode carregar. Informe o peso bruto total e o número de eixos.
Related Tools
Railway Minimum Curve Radius
Calculate the minimum railway curve radius for a design speed, R = (B·V²) ÷ (127·(h_max + I_max)), from the gauge B (mm), speed V (km/h), maximum allowable cant h_max (mm) and maximum allowable cant deficiency I_max (mm). The minimum radius is set by combining the two comfort/safety limits available to 'absorb' lateral acceleration at the desired speed: the maximum buildable cant (limited by overturning risk of slow/stopped trains) and the maximum deficiency allowed to passengers. The larger these limits, the smaller the radius for a given speed — but both have normative caps. This is central to railway alignment: it defines how sharp a curve can be without speed reduction. Sharper curves require slowing down, penalizing travel time and line capacity — so high-speed railways need huge radii (kilometers). Enter the gauge, speed, maximum cant and maximum deficiency.
Railway Cant (Superelevation)
Calculate the theoretical equilibrium cant (superelevation) of a railway curve, h = (B·V²) ÷ (127·R), from the dynamic gauge B (mm, distance between rail centers, ~1500 mm on standard gauge), the speed V (km/h) and the curve radius R (m). Cant is the raising of the outer rail above the inner one in curves, tilting the track inward — so the train's weight component helps provide centripetal force, balancing the centrifugal acceleration felt by passengers and reducing wheel-rail lateral wear. Equilibrium cant fully cancels the unbalanced lateral acceleration for a given speed; in practice a lower cant is adopted, since trains run at varied speeds on the same curve, and construction limits (~150-160 mm) apply for comfort and overturning safety of stopped trains. The difference between equilibrium and applied cant is the cant deficiency (or excess). Enter the gauge, speed and curve radius.
Track Sleeper Count
Calculate the number of sleepers needed in a track section, N = length ÷ spacing, from the section length (m) and the sleeper spacing (m, center to center). Sleepers (cross-ties) are the transverse track elements that carry the rails, hold the gauge (correct rail spacing), transmit rail loads to the ballast over a larger area, and anchor the track against longitudinal and lateral movement. Sleeper spacing (the 'sleeper density', typically 0.55-0.68 m, or about 1500-1900 sleepers per kilometre) is a design parameter depending on axle load, speed and sleeper type (wood, concrete, steel): heavy-haul lines use closer sleepers (more per km) to better spread high loads. This is essential for quantity take-off and budgeting of railway construction or renewal, since sleepers are a main track input, and for laying logistics planning. Enter the section length and the sleeper spacing.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.