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Video - Disappointment for women's relay team
Great Britain paid the price for excluding Rebecca Adlington in the women's 4x200 relay team after failing to qualify for the final on Wednesday.
The 400m freestyle gold medallist was rested, along with Caitlin McClatchey, to conserve her energy for GB's anticipated place in Thursday's final.
But the quartet of Jo Jackson, Mel Marshall, Hannah Miley and Fran Halsall failed to finish in the top eight.
Earlier, four British swimmers had made the semi-finals in their events.
But it was the controversial decision to rest some of the star names in the GB squad which dominated the agenda, with most experts predicting the event as one in which Britain had a genuine medal chance.
British 100m and 200m record holder McClatchey had also withdrawn from the 100m freestyle heats in a bid to keep her fresh for an anticipated place in the relay final.
With no McClatchey or Adlington, GB opted for the relatively inexperienced Miley and Halsall as replacements.
"We believe we made the right decision," British performance director Michael Scott told BBC Radio 5 Live.
Fran Halsall began to tire in the last 50m of the final 4x200m leg
"Obviously it hasn't worked on the day, and as performance director I accept full responsibility for that.
"The girls performed to the best of their ability. This is a disappointment but we'll bounce back from that."
The quartet began well in the second heat with 400m bronze medallist Jackson and veteran Marshall, while the inexperienced Miley swam a competent leg.
But Halsall, swimming the final leg, began to tire in the last 50m and finished in sixth.
Marshall added: "We didn't make the final so perhaps it wasn't the right call.
"I'm absolutely gutted with that - we had a chance of winning it and now we'll have to sit and watch it so it's a big disappointment for us.
"But we've got to move on very quickly and pick ourselves up."
The 18-year-old Halsall won her women's 100m freestyle heat in a time of 53.93 seconds, 0.08secs over her GB record, qualifying fifth fastest for the semis.
Gregor Tait was equally impressive, finishing second behind world record holder Ryan Lochte in a time of one minute 57.03 seconds in his qualifying heat.
"I'm very happy," said the Scot. "I actually enjoyed that, which is unusual for me. I enjoyed the swim, I felt like I was back in my area.
"The 100 isn't really my thing, it's a different stroke for me but the 200 is my stroke and I know better what I'm doing and that's why I enjoy it.
"That was my third fastest of all time and it felt pretty comfortable."
World 50m backstroke record holder Liam Tancock made a powerful start in his men's 200m individual medley heat, but faded on the freestyle leg to finish fourth.
Liam Tancock qualifed in to the individual medley semi-final
Hungarian Laszlo Cseh won the heat in a time of one minute 58.29 seconds, with Tancock 1.5secs behind, which was good enough to earn a place in the semi-finals.
He will be joined by team-mate James Goddard, who finished fifth in his qualifying heat behind the phenomenal Michael Phelps.
The American - chasing his sixth gold in the 200m IM - eased through in one minute 58.65secs, while Goddard, one lane down from Phelps, finished with one minute 59.74.
Kirsty Balfour also failed to take her semi-final place in the women's 200m women's breaststroke after finishing in sixth place in her heat.
Scot Balfour has suffered a loss in form since winning silver in the World Championships in Melbourne last year, finishing in a disappointing time of two minutes 27.87secs.
The US's Rebecca Soni won the heat, breaking the Olympic record with a time of two minutes 22.17secs.
World record holder and Athens silver medallist Leisel Jones qualified second-fastest for the semis with a time of two minutes 23.81secs.