A teenager who was preparing to set-off a homemade bomb in a crowded part of Melbourne’s CBD has been jailed for seven years for the foiled terror plot.

A judge said the 18-year-old, who cannot be named, had “every intention” of using the partially constructed pipe bombs found in his home. The only reason he didn’t go through with his plot to detonate a bomb in the CBD, on a train or at a police station was that he was arrested.

The devices the teen was making were similar to those that killed and maimed the victims of the 2013 Boston Marathon terror attacks, according to the FBI.

The youth will be eligible for parole after serving five years and three months, and has already spent more than 570 days in custody.

He admitted five boxes of screws found in his bedroom had been stockpiled for use as shrapnel.

Other items, including a pressure cooker and encrypted documents entitled “Make a Bomb in the Kitchen of your Mom” and “Pressure Cooker Backpack Bomb with Switch Detonator”, were also seized when police raided his home last May.

The bomb-making manuals set out in “alarming detail” how to construct and use a viable explosive, the court heard.

They go on to urge that the bomb should be placed in a crowded area and camouflaged with cardboard that would not inhibit their detonation.

The password protecting the documents’ encryption was Arabic for “Islamic State Forever”.

Victorian Supreme Court Justice Lex Lasry said the offending was at the “apex of seriousness” when he sentenced the youth on Wednesday.

The teen pleaded guilty to obtaining documents relating to an improvised explosive device and partially constructing an improvided explosive device (IED) in preparation for a terror act, which carries a maximum penalty of life imprisonment.

“You were part way through the construction of several pipe bombs,” Justice Lasry said.

“Your plan until it was interrupted by police was to build a bomb and detonate it.

“Had you not been arrested you would have killed and injured innocent people.”

The teen’s plan was to use shrapnel bombs to create maximum damage, much like in the 2013 Boston Marathon.

In the lead-up to his arrest, the teen had come to support ISIS and its “campaign of lies”, Justice Lasry said.

He had been in frequent contact with UK jihadist Junaid Hussein who was urging him to carry out an attack in Melbourne.

Hussein was party to a planned terror attack in London in 2013 and is believed to have been killed in Syria in August last year.

Correspondence between the two shows the teen planned to detonate an IED in either the CBD, a police station or a train.

“You thought it was what God wanted of you,” Justice Lasry said.

When police thwarted the teen’s plot, he took that as a sign from God.

Justice Lasry noted the teen’s family was supportive – some members cried throughout the sentence hearing – and he accepted the 18-year-old’s attitude to ISIS had changed.

Justice Lasry recommended that as much as possible of the 18-year-old’s non-parole period be served in a youth justice centre and that he not be kept in proximity to prisoners serving sentences for similar crimes or violent offenders.

– AAP