On ebay, there' a guy selling chain with a link size of 19mm !!!, there's very little in the way of portable tools that will get through 19mm chain. Cost is about £100 for 1.5m of 19mm chain, and there are other options.
The company that makes the chain has a website: http://www.almax-security-chains.co.uk/
The company that makes the chain has a website: http://www.almax-security-chains.co.uk/