# Placement equipment catalogue study

Reviewed 10 October 2026. This study supports the new placement calculator; it does not change the excavator/moxy calculator.

## Manufacturer references

| Crew machine / class | Catalogue reference | Values used |
|---|---|---|
| D6 | [CAT D6](https://www.cat.com/en_US/products/new/equipment/dozers/medium-dozers/15969751.html) | Push-arm SU blade 5.7 loose m³; other blade configurations differ. |
| D7 | [CAT D7](https://www.cat.com/en_US/products/new/equipment/dozers/medium-dozers/102647.html) | Standard SU blade 7 m³, rounded as displayed in the product page. |
| 815 | [CAT 815](https://www.cat.com/en_US/products/new/equipment/compactors/soil-compactors/106520.html) | Blade capacity 2.06 m³; blade width 3.761 m. |
| 825 | [CAT 825 technical specifications AEXQ3690-00, hosted by Empire CAT](https://www.empire-cat.com/sites/default/files/products/documents/CM20240320-fbcfe-e0e68.pdf) | Page 3: blade width 4.628 m, wheel width 1.125 m. No blade-volume rating is listed there; default 3.5 loose m³ per cycle is explicitly provisional. |
| 12T roller | [BOMAG BW 213 D-5](https://www.bomag.com/ww-en/machinery/categories/single-drum-rollers-soil-compactors/single-drum-rollers/bw-213-d-5-58615/) | Smooth drum reference, 12.6T, 2.13 m width. |
| 15T roller | [BOMAG BW 216 D-5 SL](https://www.bomag.com/apac-en/machinery/categories/single-drum-rollers-soil-compactors/single-drum-rollers/bw-216-d-5-sl-58446/) | Smooth drum reference, 15.36T, 2.13 m width. |
| 20T roller | [BOMAG APAC heavy rollers](https://www.bomag.com/apac-en/machinery/categories/single-drum-rollers-soil-compactors/single-drum-rollers-16-t/) | BW 219 D-5 PL smooth reference, 19.4T, 2.13 m width. Padfoot variant weights/configurations differ. |

Roller classes are the user's rounded size labels. They do not claim an exact machine weight or an exhaustive fleet catalogue. Width may be edited for an actual hired machine. Padfoot mode records the selected method and uses the edited dimensions/passes; it does not assert that a smooth reference has identical specifications in every padfoot configuration. BOMAG distinguishes smooth drums for granular/weakly cohesive materials and padfoot equipment for cohesive materials. Select the appropriate configuration and confirm by site trial.

## CAT handbook findings

Local source: `../references/Cat-Performance-Handbook-Edition-50-June-2022.pdf`. Edition 50 (June 2022) removed many current technical specifications, so model catalogues supplement it.

- Printed 10-18–10-19, PDF 151–152: single-drum roller estimates depend on working width, lift thickness, speed and required passes. Baseline table assumes 6.4 km/h and 152 mm overlap; width utilisation and short runs affect actual production. These tables are illustrative construction conditions, not a rule that every heavier roller requires fewer passes.
- Printed 16-9, PDF 228: dozing curves describe maximum loose production under specific carry/dump, traction and soil conditions. They are not a direct productivity guarantee for thin-layer spreading.
- Printed 16-18, PDF 237: blade load measured on site and a timed operation can establish production. The calculator therefore offers a measured spreading rate and an editable blade load/cycle estimate.
- Printed 19-8–19-9, PDF 293–294: compactor production is compacted volume. Metric formula is `working width (m) × speed (km/h) × compacted thickness (mm) / passes`. For CAT tamping-foot machines, use twice one wheel's width, rather than blade width or overall machine width. The required passes come from testing compacted material on site.
- The compactor production table uses 100% productive time. The calculator applies its own rest and efficiency allowances once.

The initial 815 compacting width of 1.982 m is a handbook-era wheel reference; older quick-reference data gives wheel width around 0.99 m for 815F II. The 825 compacting width of 2.25 m is also supported by the 1.125 m wheel width in CAT technical specification AEXQ3690-00, page 3. Both widths are editable; confirm the fitted wheels. Table entries contain rounding/transcription inconsistencies, so production is calculated from the dimensional formula rather than copied from individual rows.

## Implementation decisions

1. Inputs are daily target tonnes, lot width, length and layer thickness. Additional exposed inputs provide the information these four quantities cannot determine: bulk densities, shift, efficiency, compaction passes, speeds, turning time, equipment availability and wet hire rates.
2. Tonnes use one consistent moisture/mass basis. Compacted volume = tonnes / compacted bulk density. Loose volume uses loose density. For loose thickness, compacted thickness = loose thickness × loose density / compacted density. Mass is conserved.
3. Each comparison has one D6/D7 dozer or one 815/825, plus a uniform roller fleet. All counts from one to the entered available count are compared, up to a UI maximum of 100. Mixed roller sizes are outside this first version.
4. Spreading: load/cycle × 3600 gives loose m³/h. The cycle includes a push, empty return and a fixed allowance. Average push distance is entered independently of lot length and capped at the chosen run length. The fixed allowance covers loading, manoeuvring, discharging and trim. A measured rate replaces this estimate and must represent spreading alone at 100% productive time.
5. For an 815/825 doing spreading plus primary compaction, time per compacted m³ is summed: `1/spread Q + 1/primary Q`. Dozing travel is not automatically credited as validated compaction. An additional primary pass count and separate roller pass count are required. In spread-only mode, rollers perform the full entered compaction sequence.
6. Rolling lanes = `max(1, ceil((cross-lot width − working width)/(working width − overlap)) + 1)`. Whole lanes cover the lot without assuming edge overhang. Traversal = run length / speed + turn allowance. Each lane requires the entered whole passes. Rollers get separate lane groups; the slowest group has `ceil(lanes/min(roller count, lanes))` lanes. Output uses the full layer volume divided by that group's time. This causes realistic steps in the count/output curve. The CAT two-wheel width becomes an effective coverage width approximation for the primary compactor; it is not a contiguous drum footprint or dispatch simulation.
7. Crew productive capacity is the minimum of placement duty capacity and roller fleet capacity. Spreading and compaction are assumed to overlap on staged work fronts within each lot layer. A testing hold stops the entire placement fleet until results are available: no spreading or compaction occurs, and all machine hire costs continue. Actual daily output is capped by material supply (tonnes per full shift); supply is not reduced again by crew efficiency. Blank supply means unlimited material and zero means no output. Equivalent layers/day can exceed one because successive lifts reuse the lot area. The three bottlenecks are Material supply, Spreading and Compaction, including testing. Supply wins a tie. Otherwise rolling plus the testing hold is compared with placement duty time; primary compaction plus testing is compared with spreading for a shared-duty 815/825. Testing remains an additional time loss even when spreading is the main bottleneck. The detail shows capacity before and after testing holds.
8. Hire costs bill every selected machine for the full shift, including spare time and breaks. Blank/zero rates are unpriced, not free. Capacity AUD/tonne = shift hire / potential tonnes/day. AUD/m³ uses compacted volume; their ranking order is the same at fixed density. The suggested target-meeting crew minimises billed shift cost, equivalent to cost per target tonne for a fixed target. Without rates, it favours the fewest rollers among feasible crews. If none can meet the target, it reports the best capacity and shortfall.

## Explicit planning assumptions

- Compacted thickness is the initial selection; loose basis is available.
- Initial densities 1.9 compacted / 1.5 loose t/m³ are editable scenarios, not universal soil properties.
- Initial 10-hour shift, 45-minute rest, 80% work efficiency, 20 m average push, 15-second fixed spreading cycle, 150 mm overlap and 10-second turns are editable scenarios.
- Compaction testing defaults to 1 hour between full lot layers, as requested by the user; this is not a manufacturer assumption. Available clock hours = shift − rest. Working compacted m³/h = productive crew capacity × work efficiency. Production hours for one layer = layer volume / working m³/h. A full repeating cycle is those production hours plus the testing hold. Daily volume includes full cycles and the productive part of the remaining clock time; no initial hold is charged. A final layer counts when placed/compacted, without waiting for an additional test. Partial layers count as placement output, not accepted tested tonnage. Testing time used includes any partial hold at shift end when waiting to continue to another layer; when material supply is exhausted, no final hold is added. The hold is charged once per lot-layer boundary, independent of roller count, and is not efficiency-scaled. Enter 0 to reproduce the previous no-testing capacity model.
- D6/D7/815 effective blade loads assume 80% of the referenced blade capacity. CAT has not published this factor for the calculator's placement work. The 825 3.5 m³ load is provisional and requires calibration.
- All roller sizes start at 4 km/h and six passes; the 815/825 starts at 6.5 km/h and four additional primary passes. Roller passes after primary compaction also start at six. No reduction is credited solely because the compactor was present or the roller is heavier.
- Neither weight nor layer thickness automatically predicts achieved density. Increasing thickness increases estimated throughput only for the entered validated pass schedule. Thin/thick lifts, moisture, material type, amplitude/frequency and density specification must be established by site trial.
- The model includes daily material availability, initially 2,000 tonnes/day, separately from the placement target, and explicit compaction testing holds. It excludes delivery timing within the shift, watering and water-cart capacity, retesting and failed-test rework, grade/traction loss, final trim, other rework and equipment interference unless captured in entered cycles/efficiency. It does not check machine access or manoeuvring envelope. The first layer begins with no carry-over testing hold from a previous shift; the model does not carry unfinished layers/holds into a multi-day schedule.

## Verification

Run `node placement-calculator/test-engine.js` from the workspace. Tests include independent dimensional benchmarks, mass conservation, whole-lane distribution, short-run turn losses, 815/825 duty sharing, missing costs, production saturation and target/cost recommendations. Browser checks cover settings, filters, crew selection, CSV, reset, invalid inputs and responsive layout.