Analisis Produktivitas Alat Berat Pada Pekerjaan Erection Girder Menggunakan Metode Crane dan Launcher Gantry dengan Pendekatan Time Study (Studi Kasus Proyek Pembangunan Jalan Tol Bogor – Ciawi – Sukabumi Seksi 3B)

Muhamad Faiz, Ir. Nur Budi Susanto, S.T., M.Sc., IPM.

2026 | Tugas Akhir | D4 TEKNIK PENGELOLAAN DAN PEMELIHARAAN INFRASTRUKTUR SIPIL

Pekerjaan erection girder pada konstruksi jembatan tol menuntut alat berat dengan produktivitas tinggi agar pelaksanaan berjalan efektif dan tepat waktu. Metode crane dan launcher gantry umum digunakan sesuai kondisi lapangan, namun penelitian terdahulu umumnya menyajikan produktivitas secara agregat tanpa meninjau variasi antar-segmen pekerjaan (span). Penelitian ini bertujuan menganalisis produktivitas rencana dan aktual pada masing-masing metode per span, mengidentifikasi faktor penyebab variasinya, serta merumuskan upaya optimalisasi.

Penelitian dilakukan pada Proyek Jalan Tol Bogor–Ciawi–Sukabumi Seksi 3B, dengan objek Jembatan Utama Cibogo (metode crane) dan Cigempol (metode launcher gantry). Data waktu siklus dikumpulkan melalui pengamatan langsung (time study) dan wawancara. Produktivitas rencana dihitung dari waktu siklus WMS dikalikan faktor efisiensi 0,756, sedangkan produktivitas aktual dihitung langsung dari waktu siklus lapangan tanpa faktor koreksi tambahan, karena kondisi riil telah tercermin di dalamnya.

Hasil penelitian menunjukkan produktivitas rencana sebesar 0,567 girder/jam untuk metode crane dan 0,412–0,504 girder/jam untuk metode launcher gantry, dengan durasi rencana masing-masing 24 dan 25 hari. Produktivitas aktual metode crane berkisar 0,971–1,405 girder/jam dengan durasi pelaksanaan 16 hari, sedangkan metode launcher gantry berkisar 0,587–1,008 girder/jam dengan durasi 16 hari. Seluruh span pada kedua metode dikategorikan efektif, dengan peningkatan produktivitas terhadap rencana sebesar 71,30%–147,80% pada metode crane dan 42,42%–143,55% pada metode launcher gantry. Berdasarkan klasifikasi terhadap penelitian terdahulu, produktivitas kedua metode tergolong cepat. Variasi peningkatan tersebut dipengaruhi oleh kondisi cuaca, karakteristik geometrik pier, jarak span terhadap stressing bed, kompleksitas skema kerja, dan koordinasi tim pelaksana, dengan total waktu tidak efektif sebesar 168,03 menit pada metode crane dan 143,87 menit pada metode launcher gantry. Waktu siklus ideal hasil eliminasi waktu tidak efektif menghasilkan durasi optimal 16 hari untuk metode crane dan 15 hari untuk metode launcher gantry, mendekati durasi aktual yang telah dicapai. Penelitian ini merekomendasikan upaya inspeksi rutin alat, peningkatan koordinasi tim, kesiapan material bracing, dan pemantauan cuaca guna mempertahankan produktivitas mendekati kondisi ideal.

Girder erection work in toll bridge construction requires heavy equipment with high productivity so that the work can be carried out effectively and on time. The crane and launcher gantry methods are commonly used according to field conditions, but previous studies generally present productivity in aggregate without reviewing variations between work segments (spans). This study aims to analyze the planned and actual productivity of each method per span, identify the factors causing the variations, and formulate optimization efforts.

The study was conducted on the Bogor–Ciawi–Sukabumi Toll Road Project Section 3B, with the Cibogo Main Bridge (crane method) and the Cigempol Main Bridge (launcher gantry method) as research objects. Cycle time data were collected through direct observation (time study) and interviews. Planned productivity was calculated from the WMS cycle time multiplied by an efficiency factor of 0.756, while actual productivity was calculated directly from the field cycle time without an additional correction factor, as actual conditions were already reflected in it.

The results show a planned productivity of 0.567 girders/hour for the crane method and 0.412–0.504 girders/hour for the launcher gantry method, with planned durations of 24 and 25 days, respectively. The actual productivity of the crane method ranged from 0.971 to 1.405 girders/hour with an execution duration of 16 days, while the launcher gantry method ranged from 0.587 to 1.008 girders/hour with a duration of 16 days. All spans in both methods were categorized as effective, with productivity increases over the plan of 71.30%–147.80% for the crane method and 42.42%–143.55% for the launcher gantry method. Compared with previous studies, the productivity of both methods was classified as fast. These variations were influenced by weather conditions, pier geometric characteristics, the distance between the span and the stressing bed, work scheme complexity, and team coordination, with total idle time of 168.03 minutes for the crane method and 143.87 minutes for the launcher gantry method. The ideal cycle time obtained by eliminating idle time resulted in an optimal duration of 16 days for the crane method and 15 days for the launcher gantry method, close to the actual duration achieved. This study recommends routine equipment inspection, improved team coordination, readiness of bracing materials, and weather monitoring to maintain productivity close to ideal conditions.

Kata Kunci : produktivitas alat berat, erection girder, crane, launcher gantry, waktu siklus, PCI girder