PM Floodlight Masts 12–20 m: Dimensions, Anchor Cages and Scope of Application

What this range is

The PM range covers multi-sided floodlight masts 12–20 m high: a bent steel shaft carrying a fixed or lowering head frame for the floodlights. The figures in the tables come from the catalogue “Structures for outdoor lighting” (2023). The masts are made of steel S245, S255 (DBN V.2.6-198:2014) and hot-dip galvanised to DSTU EN ISO 1461:2024.

From 20 m up, the masts belong to the PMV range (20, 24, 30 and 34 m); the multi-sided equivalents of the standard PMS and PMZh form a separate PMS-B series with a platform height of 16.6–32.5 m. How the PMS, PMZh, PMV and PMK ranges differ is covered in Floodlight Masts PMS, PMZh and Our PMV, PMK; for a general overview of the product line, see Floodlight Masts.

Dimensions of PM masts

The table lists, for each height, the shaft and base-plate dimensions and the anchor cage size. A sample designation: a multi-sided floodlight mast 12 m high is PM-12.

Scope of application: floodlight area and loads

The table gives the total area of lighting fittings that a mast of each height can carry at various wind pressures (Caer = 1, terrain type III). Q is the shear force, M the bending moment at the base of the pole.

Take a PM-16 at 500 Pa: the permissible total area of fittings is 2.59 m² and the bending moment at the base is 102.05 kN·m. A PM-20 at the same pressure has almost the same permissible area (2.67 m²), but its base moment is already 153.63 kN·m. The taller the mast, the greater the moment at the base and the heavier the demands on the foundation.

Head frame: fixed or lowering

The head frame (crown) is the attachment that carries the floodlight platforms (cassettes). It comes in two versions, fixed and lowering.

• a fixed crown sits on the top section of the mast, and the floodlights are reached by a ladder to the service platform;
• a lowering crown is brought down by a raising/lowering mechanism (a winch), so the fixtures can be serviced and aimed at ground level without special equipment. It is used on high masts.

Installation, foundation and documents

Installation goes in two stages: the foundation first, then the shaft. So that it can be transported, the shaft is made in sections no longer than 12 m. Before erection the sections are drawn together with a winch, and the crown, the raising/lowering mechanism (only on high masts with a lowering crown) and the rod are then fitted. A crane sets the mast on the foundation studs.

The foundation is reinforced concrete, with a platform (a mushroom) at the bottom to resist overturning. The mast is fixed to anchor studs cast into it on two templates: the templates hold the studs in position, so the holes in the base flange match them exactly.

Construction follows the design documentation, which takes account of the soil geology and the climate of the region. The foundation design can also be ordered from our company. For more on foundation types, see Foundations for Masts, Towers and Power Line Poles.

Corrosion protection is hot-dip galvanising. The masts are supplied with a passport, an operating manual and accompanying documentation.

How to use the load table

The table was drawn up for terrain type III, Caer = 1 and equipment weighing 180 kg. Under any other conditions a separate calculation is needed.

If your wind pressure falls between two columns, take the next one up: the permissible area shrinks as pressure rises, so this leaves a margin. Below 400 Pa, use the 400 Pa column; above 600 Pa the table does not apply. The pressure for your site has to be confirmed by calculation, since W0 is only a starting point, not a final design load (see Wind Regions of Ukraine).

Height barely changes the permissible area: at 500 Pa it moves only from 2.53 to 2.67 m². The load at the base of the mast is another matter, and with it the foundation requirements. From PM-12 to PM-20 the height grows by a factor of 1.67, but the tabulated bending moment grows by a factor of 2.43 (from 63.21 to 153.63 kN·m). So do not pick a taller mast “just in case”: the height comes from the lighting calculation.

Two checks: floodlight area and mass

The table assumes equipment weighing 180 kg (a greater mass needs a recalculation), so a mast has to be checked twice: against the windage area and against the mass of the floodlights. Example for a PM-16 at 500 Pa, where the permissible area is 2.59 m² (the floodlights are hypothetical):

Area: 2.59 / area of one floodlight; mass: 180 / mass of one floodlight; rounded down. The mass of the floodlight brackets is not counted in the example. What exactly the equipment mass given in the table includes is specified in the calculation for your order; if the brackets are included, the mass limit is reached even sooner. If each floodlight has an area of 0.2 m² and a mass of 20 kg (the upper limit of the PMV range), the 180 kg assumed in the table is used up at the ninth floodlight, although twelve would fit by area. In that case you can distribute the floodlights between several masts, use the PMV range for heights from 20 m (up to 16 floodlights, 3.2 m² in total) or order an individual calculation.

What to check before ordering a PM mast

• the height is confirmed by a lighting calculation (for stadiums, masts below 15 m, i.e. PM-12 and PM-14, are not recommended; see our sports lighting guide);
• the floodlights are checked for both area and mass, and the wind pressure and terrain type are known;
• the anchor cage is ordered by its full mark. The PM-14 and PM-16 share the same M27/12 anchors but need different cages, FPM-440-850 and FPM-480-850: in an FPM mark the first number equals dimension B in the table of dimensions (440 and 480 mm) and the second is the cage height H (anchor cage sizes).