"Corrosion damages and fatigue cracks are the main causes for structural failures of all surface transport products like ships, road tankers and railway tank cars. Examples are catastrophic ship accidents with a tremendous pollution of the maritime environment or fatal explosions during the use of transport vehicles. Although evolving defects have to be identified in time to enable appropriate repair, preventive maintenance activities are usually carried out on time driven basis. As example transport products for cargo like crude oil and pressurised gases have to be taken out of service for visual inspection and sub-sequent non-destructive tests (NDT). Findings have to be repaired later on. This procedure is time consuming and expensive, especially the lost service time decreases the competitiveness of the European transport industry. Despite this high effort the risk of not detecting the onset of a defect is still implied in this maintenance process and thus failure within the next service period may occur. The proposed maintenance process is based on monitoring the status of the structural integrity in terms of developing fatigue cracks and active corrosion using the Acoustic Emission (AE) technology. It is proven, that AE detects active cracks, and based on the results of EU-funded project “corrosion detection of ship (EVG1-CT-2002-00067)”, it is evident, that AE is able to detect and evaluate active corrosion. By the application of AE sensors permanently on pre-determined hot spots of ships and tank cars the conventional maintenance and inspection can be replaced by a cost effective and condition based detection of defects and their follow-up in time. The result of the project shall be an overall strategy for the maintenance and inspection, including the necessary AE-equipment for the different transport products. Reasonable follow-up NDT methods will be validated. By the on-line measurement the method increases also the safety of all transport products."