Ultra Light Rail Partners (ULRP) draws on highly specialised skills and experience in ultra-light rail vehicles driven by biomethane and ultra-light rail engineering expertise to provide radical ultra low cost, low carbon transport innovations assisting the delivery of UK ambitions to shift to low carbon transport. This project, BioUltra, aims to deliver a critical investigation into developing a detailed design specification for up to 100 person biomethane-powered railcar building on the knowledge gained through the First of a Kind (FOAK) project known as STEAMUltra enabling the development of a biomethane powered 50-person railcar compressing the driveline into a rail bogie frame. This built on the Stourbridge Class 139 railcars in operation for over the past eleven years to-date, powered by propane and using a flywheel to provide a kinetic energy store. The aim is to develop through this new detailed design schematic a new larger railcar technical specification, operating on biomethane, and accommodating a larger passenger capacity of between 80-100 involving several new technical features to deliver a UK and world first, whilst also designed to meet specific customer and budget requirements. The BioUltra design will include Covid-19 resilient passenger experience (UX) features through ultra-violet lighting, copper fixtures on internal rails, internal plastic shielding and filtered external-internal airflows. The green gas biomethane, available from common waste products including sewage sludge, food, plant and organic waste, red-meat processing waste, poultry and cattle manure, although used worldwide to power all forms of transport including over 24 million road vehicles has not become widely adopted for transport in the UK. The use of a higher capacity light tram railcar in built and rural environments would significantly help to achieve the UK government's ambition of reaching a net zero emission status. Trams with steel wheels along steel rails require 85% less energy than wheels with inflated rubber tyres and deliver greater environmental benefits requiring significantly less energy and emitting no airborne particulates which have particular damaging impact on human health. Noxious gas emissions cause over 14k premature deaths across the UK with airborne particulates responsible for 37,800 premature deaths nationally.. This design and technical schematic will enable targeting UK and international markets drawing on sophisticated sales materials created. Immediately iIt will enable a successful pathway to the sale of two 80-100 passenger railcars for Premetro Operations Ltd (PMOL) following their expression of interest and meeting their pressing need to accommodate greater passenger capacity.