Pier

A Pier is a station Module that provides docking slots for capital ships (Ship class L and XL). Stations without piers can host only S/M ships at their built-in dockingbays; piers are how shipyards / trade stations / wharfs accommodate fleet visits.

Inheritance: component → destructible → module → pier. The datatype adds one accessor.

Properties

Pier-specific

Property	Type	Description
`.numpierdocks`	int	Number of capital-ship dock locations on this pier

Inherited

Property	Source	Description
`.numdocks.{docksize}`	module	Generic per-size dock counts (parallel mechanism)
`.haswalkableroom`	module	Walkable interior
`.hull`	destructible	Damage state

Common patterns

”Count total pier dock locations on a station”

Pattern from vanilla finalisestations.xml:759-792:

<set_value name="$Total" exact="0"/>

<do_for_each name="$mod" in="$Station.modules">
    <do_if value="$mod.isclass.pier">
        <set_value name="$Total"
            operation="add"
            exact="$mod.numpierdocks"/>
    </do_if>
</do_for_each>

<write_to_logbook
    text="$Station.knownname + ' has '
        + $Total + ' pier dock slots'"/>

Vanilla finalisestations.xml aggregates numpierdocks across all pier modules during station finalisation to know the total trade-location count.

”Filter buildable docking modules (pier OR dock area)”

<do_if value="$macro.isclass.dockarea
    or $macro.isclass.pier">
    <!-- a docking-providing module -->
</do_if>

Pattern from vanilla x4ep1_mentor_subscription.xml:9162.

Common gotchas

⚠ numpierdocks is the per-module count, not station total. Sum across all piers to get station capacity.
⚠ Pier docks are for capital ships (L/XL). S/M ships use built-in dockingbays or Dockarea modules. Don’t confuse the two.
⚠ A station with zero piers cannot host capitals. Capital ships will fail to dock; player will see “no suitable dock” error. Always check before sending capitals.
⚠ Pier dock counts are static per macro. Modders adding new pier macros set numpierdocks in the macro XML; it doesn’t change at runtime.
⚠ Vanilla also has .numdocks.{docksize} on module. This parallel mechanism counts docks by size category. For pier-specific logic prefer numpierdocks; for generic per-size counts use .numdocks.{docksize}.

Module — parent abstraction.
Station — host; aggregates pier counts during finalisation.
Dockarea — sibling, for S/M ship docking.
Ship — capital ships need piers to dock.
Build module — has its own dock mechanism for construction vessels.