This week’s problems on Greater Anglia rural routes prompted us to ask the company, along with infrastructure manager Network Rail, a series of questions about the disruption.

Today we publish the answers from the train operating company - although it is clear that in many cases they are still trying to find out how to deal with the issues.

1) We are being told that the disruption is caused by "signalling problems." Why is this only affecting services on rural routes, not on the main line between East Anglia and London?

There have been some problems with parts of the signalling system on our regional routes only in Norfolk and Suffolk. The mainline is unaffected.

The investigation is examining all factors involved in the operation of the signalling system, including how passenger trains, new and old, interact with the signalling system. Other factors being examined include the impact of extreme weather conditions and leaf fall, plus looking at components of the signalling system.

2) Are the problems linked to the introduction of the new trains on Greater Anglia's rural services - in particular are they linked to a piece of equipment called a "flange lubricator" to reduce friction between wheel and track?

At the moment, we don't know what's causing the problem with the signalling system.

The problem is very unlikely to be linked to the flange lubricator, which does not deposit lubrication onto the track and is in any case made from graphite which is a conductive material so should not affect track circuits.

3) Are the "signalling problems" linked to the incident at the level crossing on the Norwich to Cromer line when a train came within a second of being in collision with a car and is currently being investigated by the RAIB?

The incident at the Norwich Road level crossing incident is still being investigated, so we don't know what caused it and if it is related to the current signalling problems.

4) If the problems are caused by signalling problems, why are freight trains continuing to run to Felixstowe and why are East Midland Railways trains continuing to operate between Norwich and Peterborough without disruption?

While the investigation continues, both Network Rail and Greater Anglia are taking some precautionary measures, such as extra runs of Rail Head Treatment Trains, which is having an impact on frequency and availability of Greater Anglia trains. The prioritisation of which trains can run is also a Network Rail decision.

Network Rail said freight trains and other passenger operators were not having the same problem with the signalling so they were not affected by the restrictions.

5) Is this problem going to take a long time to solve (like the problems with the new Transport for London Aventra trains)?

We're really sorry, but we can't say at the moment when normal service will be resumed. But we are working closely with Network Rail to get the service back to normal as quickly as possible.

6) Has Greater Anglia trained enough drivers on the new trains and did you train them fast enough given the deadline to returning your existing rural trains to their leasing companies?

Yes, we do have enough drivers. We have been planning the introduction of new trains for three years and, of course, an essential part of our plans is staff training. The introduction of new trains on new routes is interlinked with the training of drivers for those routes.

7) Why is the Ipswich to Peterborough service withdrawn when that is one of only two routes that cannot operate new trains?

During this period of signalling problems, we've not been able to run all of our services on our rural branch lines. We've tried to minimise the inconvenience by focusing cancellations where there are best alternatives for customers. In this case, Ipswich to Peterborough customers are advised to complete their journey by train using alternative routes. We are very sorry for the delay this brings to our customers' journeys, but we are trying to ensure that all customers can complete their journeys.

8) When do you expect to know why there was a problem with the overhead collection arm (pantograph) at Elmswell last week and has this forced new checks on other trains?

The issue with the pantograph has been rectified. We are confident this was an isolated incident and not associated with the design of the train. It is not connected in anyway with the current signalling problems.

9) How will the current issue affect the introduction of the new Intercity trains that are due to start entering service before the end of the year?

We are continuing to prepare for the introduction of the new Intercity trains. They are still in the testing phase, as soon as we're confident they're ready for passenger service we'll introduce them. Clearly, our focus has been assisting Network Rail with resolving the issues with our branch lines.

10) If the problems are linked to the introduction of the new trains, why did they not show up during 2,000 miles of testing over the region's rail tracks?

At this stage, we are still investigating the cause of the signalling problems, so this is a very difficult question to answer and is unlikely to be clear until our current investigations are completed.

We have carried out a series of rigorous safety and performance tests on our new trains and they've been in passenger service since July.