The Steelhaven is an Autobot starship from the Marvel portion of the Generation 1 continuity family.

Shish kabob.

Fortress Maximus grew tired of the never-ending war on Cybertron and planned to escape it. He and other Autobots who shared in his vision of peace built the Steelhaven, a lance-shaped Autobot starship. Its destination was Nebulos, a peaceful planet which was home to small, human-like organic creatures.

Fiction

Marvel The Transformers comics

We can board vertically...

When the Autobots neared Nebulos, they parked it in orbit and descended to the surface under their own power. Ring of Hate! However, the Autobots were followed by Scorponok and his Decepticon crew, and when the Decepticons joined the Autobots on Nebulos, a war broke out that culminated in the creation of Headmaster and Targetmaster technology. To spare Nebulos from further war, both sides fled to Earth. Brothers in Armor!! The Steelhaven remained in orbit there and served as that group of Autobots' base of operation for some time.

The ship had limited resources, and a chunk of it was used during transit to Earth for rebuilding Fortress Maximus to be bigger and more powerful. Trial by Fire! Even more resources were used to repair Fortress Maximus after his defeat at the hands of Shockwave, The Desert Island of Space! to make a new body for Goldbug, and in creating Pretender technology. Pretender to the Throne! But by the time they needed to build a new body for Optimus Prime, the remaining resources on board the Steelhaven were insufficient.

...and horizontally!

Soon, the Steelhaven was introduced to the other Earth-bound Autobot ship, the Ark. A battle for Autobot supremacy followed, and both ships landed on Earth's Moon so that both sides could disembark and view the battle. Fortress Maximus kept a three-man skeleton crew aboard the Steelhaven, which proved to be the ship's saving grace when a massive Decepticon attack was launched. To protect the ship, and recreate the only Autobot he deemed truly worthy to lead the Autobots, Fortress Maximus ordered Goldbug to leave the battle and take the Steelhaven and its skeleton crew back to Nebulos, to build a new body for Optimus Prime. Totaled! The Steelhaven remained parked above Nebulos once again, while Optimus Prime and Goldbug's crew were rebuilt as Powermasters. People Power! On the way back to Earth, the Steelhaven intercepted a commercial from the Cosmic Carnival, and when it revealed that Sky Lynx was one of its stars, Optimus Prime and Goldbug investigated. The Cosmic Carnival

In 1990, the Asteroid Association erroneously listed the Steelhaven as a Nebulan ship in their Guide to the Lifeforms of the Galaxy. Transformers Annual 1991

Ask Vector Prime

The Steelhaven was disassembled so its parts could be used to repair the Ark. Whatever remained was destroyed to keep it out of human hands. Ask Vector Prime, 2015/07/08