Strikes crippled the UK Tube network on 10 and 11 June, with commuters being forced to use buses and other modes of transport.
The UK national rail union RMT called the strike following a referendum ballot of more than 11,000 engineering and administrative maintenance staff against the management's terms and conditions.
The union has been negotiating with Network Rail for the last three years.
The union is now seeking to secure a 5% rise in pay.
Some stations during the strike experienced capacity problems when lines opened temporarily.
Commuters at Clapham Junction Station, for example, took half an hour to travel between platforms and police were called to help manage the crowd.
