On Dec 3, 7:49*pm, MIG wrote:
As far as I know, only the Lewisham, Bank and Beckton branches get any
regular service with long trains, but today at least some services to
Stratford have been long.

Not entirely sure if this was down to diversions as a result of a
breakdown or a general move to increase capacity (due to so many
people diverting to DLR from troubled routes).

It's a permanent change - see:
http://www.tfl.gov.uk/corporate/medi...ive/17547.aspx

Excerpt:
---quote---
Three-car trains increase capacity on DLR Stratford to Lewisham route
30 November 2010

Three-car trains have been launched on the Docklands Light Railway
(DLR) from Stratford to Lewisham with the extra carriage increasing
capacity by 50 per cent for each train during the morning peak.
[...]
---/quote---


The following is in the notes to editors at the bottom:
---quote---
During the morning peak, every other train will run a three-car
configuration while in the evening and off peaks, the longer trains
will run according to demand.
---/quote---