BRAINTREE -- Vicar General Bishop Mark O'Connell has been hard at work for the last several weeks, leading the planning for the installation of the Archdiocese of Boston's next archbishop.

Archbishop-designate Richard Henning has put Bishop O'Connell in charge of activities surrounding his installation, to be celebrated at the Cathedral of the Holy Cross in Boston at 2 p.m. on Oct. 31. Bishop O'Connell is responsible for overseeing every aspect of the installation, and the 15 teams and 82 on-site volunteers that have been assembled for it.

In addition to its obvious spiritual significance, the installation of a new archbishop is a complex undertaking, drawing hundreds of people to the cathedral and visitors from around the country. As of Oct. 2, over 2,000 invitations have gone out, including to every bishop in the U.S.

Each of the teams has been assigned a specific aspect of the day to oversee, from the more practical, such as sending out and tracking invitation responses, coordinating seating and parking, and arranging for the needs of visiting bishops to the more overarching, such as communications and security. The heads of the teams meet once a week, under the direction of Bishop O'Connell.

"It takes an enormous amount of effort to put teams together," he told The Pilot in an Oct. 2 interview.

"I am very confident in the team," he added. "Right now, I'm not feeling the stress. I feel that our team has it together."

At least 40 bishops are expected to attend, along with priests, deacons, and members of the Order of Malta, the Order of the Holy Sepulchre, the Knights of Peter Claver and Ladies Auxiliary, and the Knights of Columbus, along with Archbishop-designate Henning's family, friends, and special guests.

"Archbishop Henning is very anxious to invite our priests and have our priests come," Bishop O'Connell said.

The maximum capacity of the cathedral is approximately 1,400 people.

"I expect it to be full," Bishop O'Connell said.

To prevent overcrowding, attendance at the installation Mass is by invitation only, but it will be broadcast live on The CatholicTV Network and will be streamed at CatholicTV.org. For those who wish to be together with others while viewing the installation, five watch parties are also being planned, one in each region of the archdiocese, at the following parishes: St. Francis in Braintree, St. Anthony in Cambridge, St. Julia in Weston, St. Theresa in North Reading, and All Saints in Haverhill.

At the cathedral, accommodations are being made for members of the media, and security will be heightened due to the presence of so many bishops, ecumenical and interfaith representatives, and politicians who have been invited.

Bishop O'Connell noted that the South End is "notorious" for its lack of parking, and encouraged those attending the installation Mass to avoid driving if at all possible.

"We are carving out as much parking as we can," he said, "but still, buses and public transportation are the ways to go."

For those who must drive, flat-rate $15 parking (payable in cash only upon arrival) has been arranged at public lots at 500 Harrison Ave., 324 Albany Street, and 365 Albany Street.

Another opportunity for the public to see Archbishop-designate Henning will come the evening before the installation day, when he will preside at a bilingual evening prayer service at St. Anthony of Padua Parish in Revere on Oct. 30 at 7 p.m. It is tradition for the archbishop to hold evening prayer the night before his installation, but it was Archbishop-designate Henning's idea to have the service primarily in Spanish as an acknowledgement of the archdiocese's large Hispanic community.

"That is a huge event to plan," Bishop O'Connell said. "We know that our Hispanic parishes and groups are very excited to send people to that, so we think it will be a full crowd."

The prayer service is open to the public.

For the installation liturgy itself, 10 priests have been tasked with "making sure that the installation goes off without a hitch" and directing the grand procession of priests, deacons, religious, and orders that will begin the Mass. The priests serving as masters of ceremonies are already rehearsing, as are the singers and musicians. Multiple choirs will provide music in several genres and languages during Mass.

"There's a lot of things that have to be done exactly right in the liturgy," Bishop O'Connell said.

The procession is scheduled to start at 1:30 p.m. The installation will begin with Archbishop-designate Henning entering the cathedral. It is traditional for him to knock on the cathedral's doors, and be welcomed by Cardinal Seán P. O'Malley, who will present the new archbishop to the assembly.

Cathedral rector, Msgr. Kevin O'Leary will present the new archbishop with a cross, which he will kiss. Msgr. O'Leary will then hand Archbishop-designate Henning vessel of holy water with which he will sprinkle the congregation.

The Mass will begin with Cardinal O'Malley as principal celebrant. Once Archbishop-elect Henning officially succeeds Cardinal O'Malley, the new archbishop will celebrate the rest of the Mass.

Cardinal Christophe Pierre, the apostolic nuncio to the U.S., will read an English translation of the papal bull, or decree, from Pope Francis naming Archbishop-designate Henning the Archbishop of Boston. Cardinal Pierre will then show the bull to the archdiocese's College of Consultors.

"That's an ancient tradition," Bishop O'Connell said. "If you think of medieval times, the new bishop comes to the cathedral. There's no internet, so he proves himself by showing the decree."

The College of Consultors inspects the decree to make sure that the papal seal on it is genuine. Once it's accepted, Cardinal Pierre will show the bull to the entire assembly.

"It's an interesting old tradition," Bishop O'Connell said.

Archbishop-designate Henning will then be led to the cathedra (seat) of the archbishop. The word cathedral originates from the cathedra, which is literally the seat of the bishop's authority. When Archbishop-designate Henning sits on the cathedra, he officially assumes his role as Archbishop of Boston, and the assembly will be invited to respond with their applause. In his homily and his remarks at the end of the Mass, Archbishop Henning will address the assembly and the whole archdiocese.

Following the installation, there will be a reception open to the public at SoWa Open Market on Harrison Ave., only blocks away from the Cathedral of the Holy Cross.

Updated information on the installation Mass and related events is available on the archdiocese's website at bostoncatholic.org/installation-mass.