Tutorial 39: Dock Details — Leveler Pits & Door Guards

A dock door is an opening. A dock is an opening plus a pit for the leveler, plus steel on every edge a forklift can reach. This lesson is the difference between the two, and it closes the Tilt-Up Concrete Association catalog.

Feature

What it is

Standard

Leveler pit

The bottom blockout of a dock leveler that houses the leveler mechanism

TCA

Door guard

Metal embeds protecting the concrete edges of a dock-leveler opening

Field practice

All of this is built today

Both features are on Dock Leveler Details, alongside the door and leveler themselves. Like Tutorial 38: Corbels, Haunches & Spandrel Seats, the reason this lesson exists is that neither is labelled with the catalog’s word for it: the pit is Lev Width and Lev Elev, and the door guard is the column headed Grd.

Note

This lesson also exists in the browser. Work it in ConstructiVision on the web — same steps, same values, so you can follow either and end up with the same panel.

What you will learn

  • Why the leveler pit is a separate feature from the leveler, and what it does to the panel’s bottom edge.

  • Why a dock opening is the one opening in the building that needs its edges armoured.

  • Why both of these are cast-in, when everything about them looks like site work.

Before you start

Lesson

Step 1 — The dock assembly

A working dock is four things, and only two of them are usually drawn:

  1. the door — the overhead door itself;

  2. the leveler — the hinged plate that bridges from the dock floor to the truck bed;

  3. the pit — the recess in the floor and the panel that the leveler folds down into;

  4. the guards — steel angle and bumpers on every concrete edge in reach of a forklift or a trailer.

Items 3 and 4 are the ones that get treated as site work and then turn out to have needed something cast into the panel months earlier.

Step 2 — Leveler pit

The pit is the box the leveler mechanism sits in. Part of it is in the floor slab; the part that concerns us is the blockout at the bottom of the panel where the pit meets the wall.

On Dock Leveler Details each row carries the dock and its pit together: Dock Elev, Dock Width and Dock Hgt describe the loading dock, then Lev Width and Lev Elev describe the leveler recess inside it. Two things follow from how they are measured, and the manual is explicit about both:

  • Dock Hgt excludes the pit. It is “the overall height of the Dock excluding the Leveler Pit” — so the two heights do not double-count, and adding them is wrong.

  • The pit is measured from the dock, not the panel. “Leveler Pit is measured from the Elevation of Dock, and the Leveler is always centered in the Main Dock.” Move the dock and the pit follows.

That last point is the same principle as the haunch in Tutorial 38: Corbels, Haunches & Spandrel Seats: the pit is derived from its dock rather than placed beside it, so the two cannot drift apart across a revision.

It is still worth understanding why the pit is not just another opening:

  • It is at the bottom edge of the panel, so it removes material from the panel’s base — where the panel bears, and where its dowels go.

  • It usually interrupts the panel’s bottom line rather than sitting inside the face, so it is a notch, not a hole.

  • Its size comes from the leveler manufacturer, not from the architecture — the same rough-opening-versus-product-size problem as the louver in Tutorial 31: Openings That Are Not Rectangles.

One thing to check by eye

A panel dowel placed where the leveler pit removes the concrete is a dowel in fresh air. Both the pit and the dowels are modeled, but they are entered on different dialogs and nothing checks one against the other — so a pit that swallows a dowel will draw without complaint.

Look at the panel base after placing a pit, and confirm the dowels sit clear of it.

Step 3 — Door guards

Every exposed concrete edge at a dock gets hit. Not might — does. Forklifts clip the jambs, trailers back into the face, and unprotected concrete corners spall within the first year.

Door guards are steel angles cast into those edges so the steel takes the impact instead. They are field practice rather than a published standard, which is exactly the kind of feature that gets left off a drawing and then added expensively.

This is one checkbox: the Grd column on the dock leveler’s row. Tick it and, in the manual’s words, ConstructiVision “places a metal embed on each side of the Dock Leveler to protect the concrete edges.”

Notice what that buys. You do not place two embeds, position each one, and keep them aligned with the opening — you assert that this dock is guarded, and the embeds are generated from the opening. Move or resize the dock and the guards follow. Placing them by hand is exactly how guards end up in the wrong place after a revision nobody re-checked; the same reasoning as the haunch in Tutorial 38: Corbels, Haunches & Spandrel Seats.

Step 4 — Why both are cast-in

Both of these feel like site work. Both have to be in the panel before it is poured.

A guard bolted on afterwards has fasteners in the impact path, which is where the assembly fails first. A pit notch cut afterwards is a saw cut through the panel’s bearing edge — the worst place on the panel to remove material without a plan.

This is the same principle as the reglet in Tutorial 32: Reglets, Brick Ledges & the Masonry Interface and it is the closing point of the whole catalog track: the panel book’s job is to know, before the pour, everything that has to be in the panel. Anything discovered afterwards is a repair.

Check your result

You should now be able to:

  • Name the four parts of a working dock and say which two commonly go undrawn.

  • Find Lev Width, Lev Elev and Grd, and say which catalog feature each one is.

  • Explain why a leveler pit is a notch in the panel’s bearing edge rather than an opening in its face, and what it can conflict with.

  • Say why Dock Hgt excludes the pit, and what goes wrong if you add the two heights.

  • Say why guards are generated from the opening rather than placed by hand.

  • Give the reason both features must be cast in rather than added on site.

Where next

A companion video for this lesson is planned alongside the written curriculum. Every step here is followable today.