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The diffusion of brake-shoe system has made it necessary to study brake–wheel–rail interactions. This study aims to elucidate this topic with an innovative small-scale test rig, the ‘4-contact machine’. A test procedure is designed in which an ER7 steel wheel is coupled with a R260 steel rail and two different brake-shoe materials (cast iron and sintered material). The results show that the 4-contact machine reproduces the effects of wheel–rail–brake shoe contact and damage similar to those observed on a railway wheel at the end of its life, highlighting marked differences in behaviour between the two brake materials.

Supercritical CO2 has been proposed as working fluid in various typology power plants, thanks to its potential higher efficiency and cost reduction with respect to well-known technology of steam cycles.However, the high operating temperature and pressure conditions pose significant concerns in terms of compatibility of the supercritical CO2 with the high temperature sections of the power block. Typically, to address this problem, samples of different materials are kept in contact with the supercritical CO2 in a pressure vessel in order to test experimentally the material compatibility. This research deals with sizing this innovative openable pressure vessel which must be able to withstand the high temperatures (700°C) and the pressures (100bar) typical of those power plants. Results obtained by analytical calculation and the finite element method are consistent. The results obtained with both methods are generalizable and applicable to each removable pressure vessel that must withstand 100 bar of pressure and a temperature of 700°C. Application field that is outside the ASME VIII div.1, standard usually used for the design of pressure vessels. It is important to underline that the use of a removable container allows to reduce the costs of compatibility tests since otherwise, after each test, the pressure vessel should be disposed of. In addition, this allows a reduction of the environmental impact due to the fact that the new container will not be disposed of after each use.