This paper provides an assessment of the lifecycle Greenhouse Gas (GHG) emissions associated with the four most common sleeper (railroad tie or cross-tie in North America) types present in the UK rail network. It estimates the embodied material, process and transport emissions linked with the lifecycle activities of construction, relay/renewal and end-of-life of these variants at low and high traffic tonnage. The analysis suggests that at low traffic loads, the softwood sleepers perform the best over the whole simulated-period. At high traffic loads, the concrete sleepers outperform all other variants in terms of lifecycle CO₂e emissions, followed by hardwood, softwood and steel. Regardless of the scenario examined, the steel sleepers perform the worst due to the carbon intensive nature of their manufacturing process. This performance gap is amplified at high traffic loads, as their service life is excessively compromised. The analysis reveals that the end-of-life pathway of timber is a critical determinant of its footprint. Results suggest that the impact of disposing of these sleepers results in their footprint being magnified. Nevertheless, if a minimum of 50% follows the combustion pathway with subsequent heat recuperation, then a GHG reduction potential of between 11% and 18% of their footprint is feasible. From a whole-lifecycle cost lens, for higher tonnage routes, the choice of concrete sleepers results in considerable financial savings. If the infrastructure manager was to install sleepers with stiff under sleeper pads (USPs), it may achieve additional economic and GHG savings, with potential for increasing the latter using recycled carbon-neutral USPs.

本文提供了与英国铁路网络中四种最常见的轨枕（北美的铁路枕木或交叉枕木）类型相关的生命周期温室气体（GHG）排放量的评估。它估计了在低吨位和高吨位下，这些变体的构造，中继/更新和寿命终止与所包含的材料，过程和运输产生的排放量有关。分析表明，在低交通负荷下，软木轨枕在整个模拟期间表现最佳。在高交通负荷下，混凝土枕木的生命周期CO ₂优于所有其他变体排放，其次是硬木，软木和钢。无论检查哪种情况，由于其制造过程的碳密集性，钢轨枕的性能都最差。在高流量负载下，这种性能差距会被放大，因为它们的使用寿命会大大降低。分析表明，木材的报废途径是其足迹的关键决定因素。结果表明，处理这些轨枕的影响会导致其占用空间增大。然而，如果至少有50％的气体沿着燃烧路径进行后续的热回收，那么将其足迹减少11％至18％的温室气体潜力是可行的。从整个生命周期的成本角度来看，对于更高吨位的航线，选择混凝土轨枕可节省大量资金。