A high ladder, or "aerial", used to fight tower block fires was dispatched immediately to the site in North Kensington as recently as 2001.
On 14 June, London Fire Brigade took 24 minutes to send a 30m (100ft) ladder.
The brigade said its policy has changed since the Grenfell Tower blaze.
The Grenfell Tower fire began on the fourth floor of the block and the first fire crews were dispatched at 00:55 BST.
Within a few hours, nearly all of the 67m (220ft) high block was ablaze.
It is thought 255 people survived the fire, and 80 people are currently missing or confirmed dead.
A BBC Newsnight investigation revealed a 30m aerial, which could have enabled firefighters to reach the 10th floor of tower, was not dispatched until 01:19 BST, 24 minutes after the first crews were sent out.
The aerial did not arrive until 01:32 BST, by which time the fire had raced up the building's cladding.
London Fire Brigade's standard procedure at the time was to send four fire engines - and no aerial platforms - to tower block fires as part of their "pre-determined attendance" procedure.
But the BBC understands previously it immediately sent an aerial to fires at Grenfell Tower as standard procedure. It is unclear when this policy changed.
The London Fire Brigade's safety plan in 2004-5 reduced the number of aerial appliances from 16 to 11.
An Audit Commission report in 2004 said the move was expected to save Â£1.75m.
Paul Embery of the Fire Brigades Union said he believes the automatic deployment of the equipment could have made a difference in tackling the fire.
"The presence of an aerial appliance very early on, being able to intervene and act as a water tower and direct large amounts of water on to the flames, could have potentially prevented the spread of that fire.
"We don't know for sure but it's a question that needs to be asked as part of the inquiry.
"The question needs to be asked in terms of the aerial appliances in London. Was it deemed they shouldn't be sent automatically as a way of saving money?"
Last week London Fire Brigade announced that an aerial platform will automatically be sent to tower fires in the future.
It said fires in high rise buildings did not routinely need an aerial appliance.
"It is important to understand that fires in high rise buildings are nearly always dealt with internally, not usually needing an aerial appliance."
"We do have aerial appliances on the attendance for specific locations and these exceptions exist if a building has been found to have particular features that mean an aerial appliance would help on-arrival firefighting tactics."

The Football Association charge relates to an incident around the 66th minute of the 2-2 draw when City were awarded a penalty.
The club "failed to ensure that its players conducted themselves in an orderly fashion", the FA allege.
Middlesbrough have until 18:00 BST on 5 May to respond to the charge.
Referee Kevin Friend awarded City a penalty for Marten de Roon's challenge on Leroy Sane.
Boro players were furious at the decision, with De Roon and Fabio booked for dissent.
High ladders which could have potentially "prevented the spread" of the Grenfell Tower fire were previously sent to the building automatically, the BBC has learned.
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Middlesbrough have been charged with failing to control their players in Sunday's Premier League match against Manchester City at the Riverside.