A coroner has cleared an expedition company of "neglect" in respect of its responsibility to protect a Wiltshire schoolboy mauled to death by a polar bear.

Ian Singleton, assistant coroner for Wiltshire and Swindon, returned a narrative verdict at the conclusion of a five-day inquest into the death of Horatio Chapple, an Eton pupil who died on an adventure holiday to the remote Svalbard islands in August 2011 with the British Schools Exploring Society (BSES) - now the British Exploring Society (BES).

The coroner found that although the group were missing items of equipment including parts of the tripwire alert system, BSES had not acted with "neglect".

He said: "I do not find that neglect is appropriate to be considered, as failure (by BSES) was not total or complete."

The teenager, from Salisbury, was sleeping in his tent when the bear went on the rampage, inflicting fatal injuries to his head and upper body on the morning of August 5.

Four others were hurt before the bear was shot dead at the camp site where the group, known as Chanzin Fire, had been staying.

Also injured during the incident were trip leader Michael "Spike" Reid, from Plymouth, Devon, Andrew Ruck, from Brighton, Patrick Flinders, from Jersey, and Scott Bennell-Smith, from St Mellion in Cornwall.

In his narrative verdict, Mr Singleton said: "On the 5th August 2011, Horatio Chapple was in a tent on a snow bridge near to the Von Post Glacier in Svalbard, Norway, as part of an expedition.

"A polar bear was able to enter the camp shortly before 7.30am undetected as the tripwire alarm system around the perimeter of the camp had failed to activate due to a supporting post more likely than not being knocked over by the bear which caused the cartridge to move or fall out of the mine without it detonating.

"Horatio emerged from his tent and was in the act of standing up when the bear reared up and slammed down on him with its paws pushing Horatio to the ground where the bear then mauled his head, face and neck causing the injury which lead to Horatio's death.

"At the time of the attack the polar bear was 24 years of age, hungry and in pain from bad teeth which more likely than not made it more aggressive and unpredictable."

The Salisbury inquest heard that the tripwire system provided by BSES worked "inconsistently" and had missing parts meaning it had to be set up in triangle shapes rather than the expected larger rectangles and that group members had modified the triggering mechanism using paper clips.

Also, the inquest was told that the group members were also expected to be kitted out with pen flares to scare off a bear but there were insufficient available and were only distributed with the group leaders.

The hearing was also told that Mr Reid attempted to shoot the bear with the group's Mauser 98K but his first attempts were unsuccessful because of the safety catch mechanism which ejected the rounds rather than fired them.

Mr Reid was praised for managing to shoot the bear after reloading the rifle after he himself had been attacked and seriously injured.

In his ruling Mr Singleton said that he believed the modifications made to the tripwire had improved the system.

He said: "I find it more likely than not the tripwire system was improved following the modifications.

"I find, having the benefit of hearing from both the leaders and members of the Fire, it's more likely than not they had been tested successfully."

He added that a tripwire system was not "100% foolproof" and said he believed the bear had hit one of the posts causing a loss of tension leading to the mines failing to fire.

He said: "On balance of probabilities I find that the corner post had been knocked down by the polar bear on entering the camp as the remaining two posts were still upright."

Mr Singleton said that the use of a tripwire system instead of a bear watch was compliant with Norwegian law.

He also ruled that the distribution of pen flares to the group members could not have helped Horatio as they were not designed for use in close range and would have taken 20 seconds or more to assemble and would not have been usable in the circumstances.

Mr Singleton ruled that Horatio had received fatal injuries immediately from his contact with the bear and Mr Reid could not have saved his life if he had managed to fire the rifle on his first attempt.

He said: "I find it more likely than not from the evidence at the scene and the findings of the post-mortem report that Horatio had received extensive injuries described in the post-mortem report which were incompatible with life."

He added: "The failure of Michael Reid to fire the rifle was not a contributing factor to Horatio's death."

Mr Singleton also ruled that the rifle was probably in the safety catch position when Mr Reid first tried to fire it.

The coroner described how a post-mortem examination of the bear found it was elderly, at about 24 years, and had worn down teeth which could have led to it being "stressed, aggressive and more unpredictable" than a younger bear.

He said: "I find that on balance of predictability that the behaviour of the bear was more aggressive and unpredictable than the majority of younger bears that were encountered in Svalbard."

Mr Singleton had adjourned the hearing after listening to legal submissions, including from Lizanne Gumbel QC, representing the Chapple family.

Ms Gumbel, in submissions, told the coroner Horatio's parents, GP Olivia and surgeon David Chapple, wished him to consider the issue of "neglect" in his conclusion.

The couple, as well as Horatio's grandfather, Field Marshal Sir John Chapple, former Army Chief of the General Staff and himself a president of the BSES, have attended all of the week-long inquest.

During the inquest, Ms Gumbel criticised BSES for providing "unsafe" equipment, particularly the tripwire system which had missing parts and had been modified using paper clips by the expedition group.

The tripwire failed to go off prior to the bear attack although the expedition leaders pointed out during the hearing that Norwegian police had suggested this was caused by the bear knocking the post over rather than not triggering the wire.

Ms Gumbel said the tripwire system was designed to protect chickens from foxes, not a campsite from a polar bear.

She said: "The fact that this child Horatio was in a campsite which was not protected was down to the society (BSES).

"The equipment that was sent out was not the suitable type of equipment in the first place."

In an independent report into the bear attack by High Court judge Sir David Steel, commissioned by BSES, he criticised the society for its reliance on the tripwire system.

He said that a bear watch should be used instead and also called for an overhaul of rifle training.

Sir David concluded: "In future a bear watch must become the norm for expeditions to Svalbard. There needs to be complete review of available tripwire systems but they should be treated only as a secondary protection device. There needs to be a rigorous upgrade of rifle training."

Mr Singleton said that he would not be preparing his own list of recommendations as he believed Sir David's suggestions and BES' implementation of them was sufficient.

He said: "I do not believe it is necessary for me to make such a report on this occasion."

Lieutenant General Peter Pearson, who is executive director of the BES, said that the organisation had adopted all of the recommendations made by Sir David in his report.

He added that he had accepted that the equipment was unsatisfactory and explained that the BES was working with a company to build a new system which was being trialled in Greenland.

Mr Pearson said: "In principle, we have accepted in the future it will be safer if there is a wire and a bear watch."

He added: "This is not a fly-by-night organisation, we tasked a High Court judge to carry out an independent inquiry which was not required, we are absolutely an open book."

The inquest previously heard the polar bear which killed Horatio was elderly and had been suffering from worn-down teeth, which would have led to it becoming stressed and behaving "more aggressively and unpredictably".

Mr Singleton said a post-mortem examination of the bear's mouth found worn down teeth caused by bad alignment, a cavity, swollen and red gums and peritonitis in several teeth.

"It's probable it affected the bear's ability to gain food and if the bear is in pain it would have increased levels of stress causing it to behave more aggressively and unpredictably than it would otherwise," he said.

Examination of the teeth showed the bear was around 24 years old, while the independent report produced by Sir David said it weighed 250kg, rather than the typical 400kg.

Horatio's parents said that they hoped new safety standards would be made mandatory to ensure future expedition groups were fully protected and to prevent further tragedies.

They also said they took comfort in their belief that Horatio's "courageous actions" may have distracted the bear and prevented other members of the group being killed.

The family called for BS8848, the British Standard for organising expeditions outside the UK which was first drafted in 2007 with a revised version released this April, to be made into law.

They said: "We hope now that the British Standard 8848 will become mandatory to protect other children like Horatio, who want to explore the world.

"These sensible guidelines were developed for organisations taking children on adventurous activities abroad, so that any parent handing their child into the care of a provider can be assured that the venture has been professionally planned and managed."

The Chapple family also called on parents to ensure they inspect expedition companies before sending their children abroad.

She said: "We would urge parents to question the organisations who may be taking responsibility for the lives of their children. Ask the uncomfortable questions and only trust if you are completely satisfied with the answers."

They added: "Our solace is the 17 years of love, kindness and courage, which Horatio gave to so many of us.

"In Horatio's memory we are creating a legacy of beautiful therapy gardens in spinal injury centres, for people whose lives have been devastated by injury.

"The first Horatio's Garden was opened at the Duke of Cornwall Spinal Treatment Centre in Salisbury in 2012 and the charity Horatio's Garden is now raising money for further gardens around the UK to plant hope for people living with paralysis."

The family also described the version of events which they understand from the evidence given at the inquest including that Horatio may have helped prevent others from being killed.

They said: "Anyone listening to the evidence during this inquest will understand our sorrow at the nature of Horatio's death and the terrible ordeal experienced by all those on the trip.

"From the accounts we have heard, we take some small comfort from the fact that Horatio's courageous actions may have distracted the bear, preventing others from being killed.

"From the evidence, we have been able to establish the sequence of events.

"The morning of the attack the weather was clear and visibility good. The bear would have been attracted to the sleeping campsite by unusual smells and seen the tents as large walrus-sized shapes.

"The bear circled the near tent and probed the outer material with its paws and mouth waking Horatio and his two younger companions.

"They were unsure of what was happening and the rest of the camp was deeply asleep. On realising that it was a bear pawing and shaking their tent, Horatio and his companions started shouting 'bear'. These shouts woke some of the other tents, but there was no verbal reply from the leaders.

"After several seconds of shouting with no reply, Horatio tried to get out of his tent. The bear attacked him as he was trying to stand. In the attack, the bear collapsed the tent over the other two who then remained still and quiet.

"Horatio managed to stand despite severe wounds to his head and was seen by witnesses facing the bear, confronting the bear with all that he had, his screaming voice, his empty hands and raised arms.

"At this point, Horatio's best chance would be that the leader could save him by shooting the bear with the only gun available.

"The gun, a Mauser 98K, was stored in the leaders' tent with the trigger released on an empty chamber. In this state the safety catch cannot be moved. The leader picked up the gun then worked the bolt, which chambered a round.

"The mechanism of this type of gun only allows the safety catch to be moved from the left to the fire position at this point. If not moved round, the bolt can be worked but the trigger mechanism is still locked. So when the leader took aim, the bullet did not release. In all, the leader aimed four times but with the safety catch still in position, he was forced to eject each round.

"During this attempt to use the rifle, the polar bear rose onto its hind legs to its full height of nearly four metres (11 feet) and then came down onto Horatio knocking him to the ground and continuing to attack him.

"The bear then moved to attack the leader who dropped the gun with the bolt open. Another Young Explorer retrieved the gun and managed to enter the leaders' tent. Putting the gun down inside, he then searched but could not find the hidden spare ammunition. The leader returned to the tent, saw the gun and reloaded it with one of the previous rounds that had fallen to the ground.

"Once the bolt was closed the safety catch mechanics allowed it to be moved on one more position to the far left finally allowing the trigger to be released. So the bullet fired and the bear was killed."

Edward Watson, BES chairman, said in a statement: "The society does not intend to make any statement regarding the outcome of the inquest at this stage.

"Again may I express our deepest sympathy to the Chapple family."