This is a character level complete starship combat system designed to replace the abstract system in the T4 core rules book. The system was prepared by a number of Traveller Mailing List Luminaries, including Joe & Carole Walsh, Eris 'the Heretic' Reddoch, Guy 'Wildstar' Garnett and Allen Shock. (Author Walsh, Reddoch et al. 136 kb).
This document is a complete starship combat system for T4. It amalgamates and builds on elements of Classic Traveller's MayDay, Fire, Fire Fusion & Steel 2, Battle Rider and the 'Definitive Sesnor Rules' by Bruce Alan Macintosh. This system is aimed at Fleet level combat - if you're after player characters look at the Roleplaying Space Combat System below. (Author Sean Bayan Schoonmaker, PDF 67kb).
This is the Quick Ship Design System from T4, with all the errata fixed including the HEPlaR fuel error in the original release. Build starships for your T4 game without the need to use the detailed 'Fire, Fusion and Steel 2' system. (Author Guy 'Wildstar' Garnett, PDF 128 kb).
This document expands the basic list of hulls in QSDS with a further 56 (!) pages of different hull forms from 100dT through to 5,000dT (Author Guy 'Wildstar' Garnett, PDF 903kb).