Project Case Study · Ulaanbaatar, Mongolia

A Mining Steel Workshop in Ulaanbaatar — 48 × 18 m Portal Frame for a −40 °C Site

The first shipment reached the site before the drawings had finished being argued over. The client sent a photo of the container doors opening — H-beams stacked and banded, frost on the tarpaulin — and then a question: which way do the wall panels go on?

That question turned out to be the project in miniature. This was an Ulaanbaatar mining company’s first purchase from China, its first portal frame building, and its first attempt to put aluminium-framed glass curtain wall into a workshop standing on open steppe. The building runs 48 m long by 18 m wide, 6 m to the eaves, is wrapped in 100 mm PU sandwich panels on both walls and roof, and carries a mezzanine office level inside. It was designed, fabricated and shipped in two container loads, and it went up on the planned three-month schedule with a local crew and our engineers on video call.

• Location: Ulaanbaatar, Mongolia
• Building: 48 m × 18 m × 6 m eave
• Floor area: 864 m² + mezzanine
• Structure: Portal frame
• Envelope: 100 mm PU sandwich panel

What a mine actually needed from this building

Mining carries Mongolia’s export economy, and the work around it — equipment maintenance, spare parts, tools, site administration — needs covered space that behaves differently from a logistics warehouse. A distribution centre moves pallets. A mine building holds diesel-fumed machinery, steel-track components, welding gear and the people who maintain all of it, often in the same volume of air.

Our client is a mining operator based in Ulaanbaatar. The company name and site location stay off this page at their request. What they needed was one building doing three jobs: covered storage and maintenance space on the ground floor, a mezzanine level for offices, and a front elevation that did not look like a shed — because this building also receives visitors.

They came to us sideways. A design company working for one of our earlier Mongolian customers passed our contact details on. They had already spoken to two or three other suppliers, the yard was cleared and waiting, and the budget was the part they watched most closely. That shaped everything that followed.

Four things the site handed us, and what we did with each

The build in numbers

The Project at a Glance

Why the drawings went through three revisions

Most project pages say “design finalised” and move on. This one went back and forth more than three times, and it is worth saying why, because the reasons are the ones that come up on almost every mine building.

The first revision was the mezzanine. Putting an office level inside a portal frame changes what the frame has to carry and where the stair goes; the first layout put the stair where it ate the clearest part of the working floor. The second was the curtain wall opening — glass in a steel-framed elevation is not a window in a wall panel, it needs its own supporting steel and its own tolerance, and the original elevation drawing left that to the erector. The third was the wall panel layout itself, and that one only became obvious once the client’s crew stood in front of the crate.

None of these were structural errors. They were details that a drawing office can reasonably leave general, and that a first-time erector cannot reasonably be expected to resolve alone.

Two containers, one fragile crate, and a second packing job

Mongolia is supplied overland, not by sea. Steel for Ulaanbaatar runs north from our Zhengzhou plant to the Erenhot–Zamyn-Üüd crossing and on up to the capital — a route we run often enough to know where the delays sit and what paperwork holds them up.

The trouble on this one was not the steel. It was the glass curtain wall. Glass and aluminium profile do not tolerate the handling that structural steel shrugs off, and the first packing was not good enough for an overland route with transloading at the border. We had it re-packed into wooden crates before dispatch, and the PU panels were strapped and banded tightly enough to survive being moved more than once.

From unloading to weathertight

The wall panels that went on sideways

Here is the part the client’s photo was actually asking about. These wall panels are laid horizontally, not vertically, and they are concealed-fix — the fasteners are hidden in the panel joint rather than driven through the face. On a finished elevation that looks clean. On a first erection it looks unfamiliar, and the sequencing is not intuitive: start at the wrong end and every subsequent panel fights the one before it.

The crew stopped and asked rather than guessing, which was the right call. We sent photos and a short video of the same panel being installed on an earlier job, walked the starting corner and the fixing sequence over a call, and stayed on until the first three panels were up and the crew was happy with the rhythm. From there it moved on its own.

The curtain wall was harder, and mostly for a reason that had nothing to do with the product: the crew could not find where it was meant to sit. That is a drawing problem, so we fixed it with drawings — dedicated installation drawings with the opening dimensions, the supporting steel and the fixing details dimensioned, so the position could be set out rather than judged by eye.

An office inside a workshop

The client wanted the building to look like a company headquarters, not a stores hut. That is a reasonable ask when suppliers, inspectors and mine staff walk through the same door, and it is why the office elevation carries aluminium-framed glass curtain wall while the rest of the building is clad in PU sandwich panel.

Inside, the mezzanine holds the offices, partitioned in the same PU panel as the envelope. That detail matters more than it sounds: partitioning the office level in a different material would have put a thermal break in the middle of the building, and the offices would have been the coldest rooms in it. As built, the office level sits inside the same insulated box as the workshop floor.

How it landed

In our post-handover review the client rated the project 9 out of 10, and agreed to recommend Canglong on LinkedIn. We are not publishing a testimonial under their name here — at their request the company and the site stay off this page — but the reference is available to serious enquirers who ask.

We are publishing the 9 rather than rounding it up, because the number is only worth anything if it means something. There were three-plus drawing revisions, a repacking job before dispatch, and a crew that had to be talked through the first wall panels. Those were resolved, not airbrushed, and the building was handed over inside the three-month programme the client planned around.

What the client said mattered most in choosing us was not any single one of those things. It was that the same supplier had run Mongolia before: the Erenhot route, the way these buildings get used, which materials hold up here, and which ones are a mistake.

Watch it from the site

Planning a building for a mine site?

If you are pricing covered space for maintenance, parts storage or site administration in Mongolia — or anywhere with a winter that sets the programme — talk to the person who ran this one. She will ask what goes in the building before she asks how big it is.