Census website goes offline

Offline: Apology on the PRO website about census

By BBC News Online's technology correspondent Mark Ward

Overwhelming demand has forced the Public Record Office (PRO) to take the England and Wales 1901 census website offline.

The numbers have been quite unprecedented

BT spokeswoman

No-one will be able to reach the census site for a week while the PRO puts in place computer systems that can cope with the huge demands web users are making on the survey.

Since the site went live last week, it has been getting up to 30 million hits per day.

Although steps have been taken to let more people reach the site, the sheer number of visitors has overwhelmed even these stop-gap measures, forcing the website to be shut down while it is re-engineered.

Crowded house

Almost from the moment the 1901 census site was launched on 2 January, it has struggled to cope with the crowds of net users who have turned up to search the archive for mentions of relatives or the street or house they live in.

A spokeswoman for BT, which looks after the computers that hold the 1901 census, said originally the site was designed to cope with around one million hits per day.

"At the time that was thought to be a generous estimate of visitors," she said.

In the event, up to one million users at once have been trying to search the site, and, if every one had got through, daily totals would have nudged the 30 million mark.

Clogging the network

"The numbers have been quite unprecedented," she said.

The number of "hits" does not equal actual users and much of the traffic may have been generated by people repeatedly trying to reach the site.

The Queen Mother: One of the names on the census

BT itself has been forced to limit the numbers that can reach the site for fear that the volume of traffic flowing towards the PRO census would clog its network and affect visitors to every other site that BT looks after.

In an attempt to lighten the load on the computers, or servers, that push information out to net browsers, the PRO has simplified the information on each page to make it smaller.

But this has hardly made any difference. The PRO is now taking the drastic step of shutting the whole site down so it can rebuild.

"No-one is going to be able to get through to the census site for the next week," said a spokeswoman for the PRO.

During that time the PRO technical team and its partners BT and Qinetiq are re-engineering the site to ensure it can cope with the millions of hits it is getting.

Hard copy

The PRO has also said it will not charge those people who used credit cards in the last week to buy hard copies of census pages in which they were interested.

Those desperate to use the site can visit the Family Records Centre in Islington, which has 40 computers that will remain connected to the site for the next week.

Microfilm copies of the 1901 census are also available in the local record centres dotted around the country.

The online version of the census makes available personal information about 32 million people living in England and Wales at the turn of the century.

The Public Record Office is not the first organisation to be caught out by the unexpected demand for its services. Encyclopaedia site Britannica was offline for weeks when it put its reference works online for people to browse.