Firefighters rescued two men trapped on the fifth floor of Grenfell Tower by propping a 13.5-metre (45ft) ladder against the outside of the building, the inquiry into the fire has been told.

On the sixth day of evidence from crews who attended the blaze, efforts to evacuate residents from the floors immediately above the flat where the fire started were revealed.

Thomas Abell, who drove one of the first pumps to arrive at the scene in the early hours of 14 June last year, said in a statement there was no sign of smoke or flames at that stage.

But in less than an hour the fire had spread across the face of the tower. “I remember thinking: ‘This is going up like rocket fuel,’” he said.

The inquiry was shown a video of the fire from 1.15am as it began to rip through the exterior cladding, showering the ground with burning debris and liquid.

By about 1.45am, Abell said, “the flames had consumed more than half of one side of the tower, they were ferocious flames. It was completely unprecedented; a fire in a tower block should not spread like this. Fires are normally fought from the inside and not the outside.”

Abell, who joined the London fire brigade in 2011, initially helped set up a “covering” hose to prevent the flames spreading from the fourth floor flat where the fire began. He was then tasked with conducting “search and rescue” operations on the fifth floor, helping to evacuate a family of four who were in one flat.

He and a colleague then forced their way into the flat above the one where the fire started. “I just kicked the door in,” he said. “Almost immediately a thick plume of smoke came out … I could see thick black smoke, this was to floor level and visibility was zero. I was very surprised at this and I started to feel concerned.”

He sprayed the flat with a hose. “It was hard to identify any source of fire and all the fire fighting techniques I deployed were not having any effect on the fire.” His hose snagged and a colleague went to fix it.

Inside the flat, it become hotter and hotter. Abell was eventually forced to retreat. He only found his way back to the front door by following the hose. Outside, he found his colleague and went back down to the fire control.

He was sent to set up water supplies to jets and then assisted firefighters trying to manoeuvre ladders up the side of the tower. “I could see there were many people leaning out of windows on various floors of the tower trying to get our attention. They were doing this by shining lights and waving towels.”

The first ladder they used was nine metres (30ft) long. They put it up from the mezzanine floor but realised it was not long enough. With help from several residents, they hauled up a 13.5 metre (45ft) ladder.

“This was achieved by some of us pushing the ladder up from the ground floor whilst others pulled from the mezzanine level ... we pitched the ladder to the fifth floor apartment where the two males were signalling for our attention.”

Abell climbed up. “Once I had got to the window where the two males were, I performed a rescue of one of the males. I did this by coaching him on to the ladder. Understandably this took a bit of time as it was a daunting experience for the male, but slowly he managed to climb on the ladder and descended to the mezzanine level.”

Another firefighter rescued the second man but no one else appeared at the window. Abell noticed a man on the 16th or 17th floor knotting sheets together to make a rope he was planning to descend. There were already flames nearby.

“I shouted as loudly as I could,” Abell said. “I instructed him to stay where he was and not to try and exit the building via the window.” He subsequently met the man, named as Oluwaseun, who escaped safely from the fire.

Abell spent the rest of the night operating water jets from the ground as burning cladding plummeted down the outside of the tower. One piece set light to a car, which had to be extinguished, while another split open a hose.

Later Justin O’Beirne, a firefighter from the north Kensington station with 20 years experience, gave evidence of poor radio communications. He climbed to the floors above the initial fire and called back to warn his superiors of flames and smoke spreading to other flats.

“I only radioed once,” O’Beirne said. “I don’t remember hearing any other radio traffic at that time. I didn’t get a reply … Normally you would get a reply however in my mind at the time I assumed the governor was doing other stuff but that they would get another crew upstairs.”

Eventually he met colleagues and told them a fifth floor flat was alight. One of them was trying to turn the valve on the dry riser the wrong way. “I think I said to him ‘you idiot, you’re doing it the wrong way’,” O’Beirne said.

He kept on climbing up the stairwell to discover whether other flats were on fire or smoke-logged. He believed it was safe to leave residents in flats that were not affected. He said he was exploring without having told his superiors where he was heading.

Finding more smoke, he radioed again to Watch Manager Dowden. “I didn’t get a reply to any of the radio messages I sent to the governor but I assumed he was still very busy but that he could hear me.”

By the time he reached the 8th floor and met more smoke, O’Beirne said he began to realise “we are not going to get enough people down to the tower to rescue everyone”.

He stopped between the 11th and 12th floors to puzzle out why there was so much smoke in the lobbies. “I couldn’t hear any alarms and there was just an eerie silence. I didn’t hear any alarms going off at all while I was in the tower.”

He added: “When I was standing still having a think on the half landing, I heard a scream...” He went up to the next landing. After a few seconds a woman shot out from that floor into the stairwell on her hands and knees which gave me a bit of a fright.” She disappeared down the stairst.

Two residents came down the stairs. One told O’Beirne his father was bed-bound on the 16thfloor. Not wearing breathing apparatus, the firefighter radioed for help.

Two colleagues sent up to search brought down others from that floor but couldn’t reach the older man.

“Although they didn’t actually say that the guy they had been looking for on the 16th floor would be dead, they were telling me that from the information they had given me … It was so hot they couldn’t get to him and it wasn’t worth putting themselves at any more risk, as the guy wouldn’t be able to survive in those conditions for more than three minutes. I knew that the guy’s dad wasn’t going to be alive.”

The inquiry continues